Initial public release

.cargo/config.toml

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+# Cross-compilation targets for NotAlterra
+#
+# Requires: sudo apt install mingw-w64    (Debian/Ubuntu)
+#           sudo dnf install mingw64-gcc  (Fedora)
+#
+# Build:
+#   cargo build --release --target x86_64-pc-windows-gnu
+#   cargo build --release                     # Linux native
+
+[target.x86_64-pc-windows-gnu]
+linker = "x86_64-w64-mingw32-gcc"

.gitignore

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+/target
+/NotAlterra_Backups
+/samples
+*.log
+config.ini
+.deepseek

Cargo.toml

@@ -0,0 +1,26 @@
+[package]
+name = "notalterra"
+version = "0.3.0"
+edition = "2021"
+authors = ["NotAlterra"]
+license = "MIT"
+description = "Subnautica 2 save-file manager — cross-platform terminal application"
+
+[dependencies]
+ratatui = "0.29"
+crossterm = "0.28"
+nom = "7"
+chrono = "0.4"
+dirs = "5"
+sysinfo = "0.33"
+regex = "1"
+anyhow = "1"
+log = "0.4"
+simplelog = "0.12"
+unicode-width = "0.2"
+
+[profile.release]
+opt-level = 2
+lto = true
+strip = true
+codegen-units = 1

LICENSE.md

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+MIT License
+
+Copyright (c) 2025 NotAlterra
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# NotAlterra
+
+**Subnautica 2 save-file manager — cross-platform terminal application.**
+
+NotAlterra is an unofficial tool for managing Subnautica 2 save files. It locates your save folders, backs up and restores `.sav` / `.bak` files, and lets you inspect the internal metadata of every save.
+
+Not affiliated with Unknown Worlds Entertainment or KRAFTON.
+
+---
+
+## Features
+
+- **Auto-locate** save folders across Steam, Xbox, Epic, and custom installs
+- **Recover** a corrupted `.sav` from its `.bak` backup with rollback
+- **Create / restore** full backups (only `savegame_*` files)
+- **Manage** UE5 Config `.ini` files — backup, restore, delete
+- **Inspect** any `.sav` or `.bak` file — full GVAS metadata dump
+- **Slot grouping** with Online / Local detection
+- **Warns** on name changes and online↔local mode switches before recovery
+- **Game-running guard** — exits or warns if Subnautica 2 is active
+- **Transaction log** — all actions timestamped to `transaction.log`
+- **Cross-platform** — Linux and Windows console builds
+
+---
+
+## How to Build
+
+```bash
+# Linux
+cargo build --release
+
+# Windows (from Linux with mingw-w64)
+rustup target add x86_64-pc-windows-gnu
+sudo apt install mingw-w64
+cargo build --release --target x86_64-pc-windows-gnu
+```
+
+---
+
+## Usage
+
+Run the binary. On first launch it auto-scans for your save folder. The menu is keyboard-driven:
+
+| Key | Action |
+|---|---|
+| `↑` `↓` | Navigate |
+| `Enter` | Select |
+| `Esc` | Cancel / Back |
+| `Y` / `N` | Accept / Decline in dialogs |
+
+### Menu
+
+1. **Recover .sav from .bak** — pick a backup, preview metadata, overwrite the live save
+2. **Create full backup** — copies all `savegame_*` files to `NotAlterra_Backups`
+3. **Restore full backup** — overwrite the save folder from a previous backup
+4. **Inspect save files** — view all GVAS properties of any `.sav` / `.bak`
+5. **Manage UE5 Config (.ini) files** — backup, restore, or delete `.ini` files
+6. **View disclaimer**
+7. **Exit**
+
+---
+
+## Where Files Live
+
+```
+%LOCALAPPDATA%\Subnautica2\Saved\SaveGames\
+    savegame_0.sav
+    savegame_0.bak
+    savegame_0_1.bak
+    savegame_1.sav
+    ...
+```
+
+Backups are stored in `NotAlterra_Backups\` alongside the binary.
+
+---
+
+## config.ini
+
+Created automatically next to the binary:
+
+```ini
+[alterra]
+last_path = C:\Users\...\Subnautica2\Saved\SaveGames
+last_scan = 2026-05-31 18:00:00
+disclaimer_accepted = true
+config_path = C:\Users\...\Subnautica2\Saved\Config\Windows
+```
+
+Delete `config.ini` to force a fresh scan on next launch.
+
+---
+
+## Safety
+
+- Runs in your user context — no admin privileges required
+- No network connections
+- Read-only inspect mode won't touch files
+- Pre-restore snapshots created automatically
+- Guard against file corruption: refuses overwrite if Subnautica 2 is running
+
+---
+
+## License
+
+MIT — see `LICENSE.md`.

build.sh

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+#!/usr/bin/env bash
+set -euo pipefail
+
+# NotAlterra release build script
+# Produces: target/release/notalterra (Linux)
+#           target/x86_64-pc-windows-gnu/release/notalterra.exe (Windows)
+
+VERSION=$(grep '^version' Cargo.toml | head -1 | sed 's/.*"\(.*\)".*/\1/')
+echo "=== NotAlterra v${VERSION} ==="
+
+# Ensure Windows target is installed
+if ! rustup target list --installed | grep -q x86_64-pc-windows-gnu; then
+    echo "Installing Windows target..."
+    rustup target add x86_64-pc-windows-gnu
+fi
+
+# Check for mingw linker
+if ! command -v x86_64-w64-mingw32-gcc &>/dev/null; then
+    echo "WARNING: mingw-w64 not found — Windows build will be skipped."
+    echo "Install it: sudo apt install mingw-w64"
+    WINDOWS_SKIP=1
+else
+    WINDOWS_SKIP=0
+fi
+
+echo ""
+echo "Building Linux release..."
+cargo build --release
+
+if [ "$WINDOWS_SKIP" -eq 0 ]; then
+    echo ""
+    echo "Building Windows release..."
+    cargo build --release --target x86_64-pc-windows-gnu
+fi
+
+echo ""
+echo "=== Build complete ==="
+echo ""
+ls -lh target/release/notalterra
+if [ "$WINDOWS_SKIP" -eq 0 ]; then
+    ls -lh target/x86_64-pc-windows-gnu/release/notalterra.exe
+fi

examples/dump_samples.rs

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+//! Dump GVAS metadata for all .sav/.bak files in `samples/`.
+//! Run: cargo run --example dump_samples
+
+use chrono::TimeZone;
+use std::fs;
+use std::path::Path;
+
+fn main() {
+    let dir = Path::new("samples");
+    let mut entries: Vec<_> = fs::read_dir(dir)
+        .unwrap()
+        .filter_map(|e| e.ok())
+        .filter(|e| {
+            let s = e.file_name().to_string_lossy();
+            s.ends_with(".sav") || s.ends_with(".bak")
+        })
+        .collect();
+
+    entries.sort_by(|a, b| {
+        let ma = a.metadata().ok().and_then(|m| m.modified().ok());
+        let mb = b.metadata().ok().and_then(|m| m.modified().ok());
+        mb.cmp(&ma)
+            .then_with(|| a.file_name().cmp(&b.file_name()))
+    });
+
+    println!(
+        "{:<8} {:<26} {:<6} {:>7}  {:<19}  {:<28}",
+        "", "Display Name", "Type", "Size", "Date", "File"
+    );
+    println!("{}", "-".repeat(115));
+
+    let mut seen = std::collections::HashSet::new();
+    for entry in &entries {
+        let path = entry.path();
+        let name = entry.file_name().to_string_lossy().to_string();
+        let size = entry.metadata().map(|m| m.len()).unwrap_or(0);
+        let mtime = entry
+            .metadata()
+            .ok()
+            .and_then(|m| m.modified().ok())
+            .and_then(|t| {
+                let secs = t.duration_since(std::time::UNIX_EPOCH).ok()?.as_secs();
+                chrono::Local
+                    .timestamp_opt(secs as i64, 0)
+                    .single()
+            })
+            .map(|dt| dt.format("%Y-%m-%d %H:%M:%S").to_string());
+
+        let meta = notalterra::gvas::extract_metadata(&path).ok();
+        let slot = meta.as_ref().and_then(|m| m.slot_name.clone()).unwrap_or_else(|| {
+            notalterra::gvas::derive_slot_from_filename(&name).unwrap_or_else(|| "?".into())
+        });
+        let display = meta
+            .as_ref()
+            .and_then(|m| m.display_name.clone())
+            .unwrap_or_else(|| "(unnamed)".into());
+        let is_online = meta.map(|m| m.is_online).unwrap_or(false);
+
+        let label_num = slot.strip_prefix("savegame_").unwrap_or(&slot);
+        let first = seen.insert(slot.clone());
+        let label = if first { format!("Slot {label_num}") } else { String::new() };
+
+        let typ = if is_online { "Online" } else { "Local" };
+        let sz = if size < 1024 {
+            format!("{size} B")
+        } else if size < 1024 * 1024 {
+            format!("{:.0} KB", size as f64 / 1024.0)
+        } else {
+            format!("{:.1} MB", size as f64 / (1024.0 * 1024.0))
+        };
+
+        println!(
+            "{label:<8} {display:<26} {typ:<6} {sz:>7}  {:<19}  {name:<28}",
+            mtime.as_deref().unwrap_or("?"),
+        );
+    }
+}

src/config.rs

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+//! config.ini read/write.
+//!
+//! The file sits next to the binary and stores cached paths plus the
+//! disclaimer-acceptance flag.  Format is a flat `[alterra]` section:
+//!
+//! ```ini
+//! [alterra]
+//! last_path = C:\Users\...\Subnautica2\Saved\SaveGames
+//! last_scan = 2026-05-26 19:45:22
+//! disclaimer_accepted = true
+//! config_path = C:\Users\...\Subnautica2\Saved\Config\Windows
+//! ```
+
+use anyhow::{Context, Result};
+use std::fs;
+use std::io::{BufRead, BufReader, Write};
+use std::path::{Path, PathBuf};
+
+/// In-memory representation of the config.ini keys.
+#[derive(Debug, Clone, Default)]
+pub struct AppConfig {
+    /// Last-known save folder (SaveGames)
+    pub last_path: Option<String>,
+    /// Last-known Config\Windows folder
+    pub config_path: Option<String>,
+    /// Timestamp of last successful scan
+    pub last_scan: Option<String>,
+    /// Whether disclaimer was accepted
+    pub disclaimer_accepted: bool,
+}
+
+/// Path to config.ini alongside the binary.
+pub fn config_path() -> PathBuf {
+    let exe_dir = std::env::current_exe()
+        .ok()
+        .and_then(|p| p.parent().map(Path::to_path_buf))
+        .unwrap_or_else(|| PathBuf::from("."));
+    exe_dir.join("config.ini")
+}
+
+/// Read and parse config.ini.
+pub fn load_config(path: &Path) -> Result<AppConfig> {
+    let mut cfg = AppConfig::default();
+
+    if !path.exists() {
+        return Ok(cfg);
+    }
+
+    let f = fs::File::open(path)
+        .with_context(|| format!("cannot open {}", path.display()))?;
+    let reader = BufReader::new(f);
+
+    for line in reader.lines() {
+        let line = line?;
+        let trimmed = line.trim();
+
+        if trimmed.is_empty() || trimmed.starts_with('[') {
+            continue;
+        }
+
+        if let Some(val) = trimmed.strip_prefix("last_path").and_then(strip_eq) {
+            cfg.last_path = Some(val.to_string());
+        } else if let Some(val) = trimmed.strip_prefix("config_path").and_then(strip_eq) {
+            cfg.config_path = Some(val.to_string());
+        } else if let Some(val) = trimmed.strip_prefix("last_scan").and_then(strip_eq) {
+            cfg.last_scan = Some(val.to_string());
+        } else if let Some(val) = trimmed.strip_prefix("disclaimer_accepted").and_then(strip_eq) {
+            cfg.disclaimer_accepted = val.trim() == "true";
+        }
+    }
+
+    Ok(cfg)
+}
+
+/// Strip `=` and surrounding whitespace.  Returns `Some(value)`.
+fn strip_eq(s: &str) -> Option<&str> {
+    Some(s.trim().strip_prefix('=')?.trim())
+}
+
+/// Write config back to disk, preserving non-managed keys.
+pub fn save_config(path: &Path, cfg: &AppConfig) -> Result<()> {
+    // Preserve unknown keys by reading the old file first.
+    let preserved = preserved_keys(path).unwrap_or_default();
+
+    if let Some(parent) = path.parent() {
+        fs::create_dir_all(parent).ok();
+    }
+
+    let mut f = fs::File::create(path)
+        .with_context(|| format!("cannot write {}", path.display()))?;
+
+    writeln!(f, "[alterra]")?;
+
+    if let Some(ref lp) = cfg.last_path {
+        writeln!(f, "last_path = {lp}")?;
+    }
+    if let Some(ref cp) = cfg.config_path {
+        writeln!(f, "config_path = {cp}")?;
+    }
+    if let Some(ref ls) = cfg.last_scan {
+        writeln!(f, "last_scan = {ls}")?;
+    }
+    writeln!(
+        f,
+        "disclaimer_accepted = {}",
+        cfg.disclaimer_accepted
+    )?;
+
+    // Append any extra keys we didn't touch
+    for (k, v) in &preserved {
+        writeln!(f, "{k} = {v}")?;
+    }
+
+    Ok(())
+}
+
+/// Collect key/value pairs from the old config that this tool doesn't own.
+fn preserved_keys(path: &Path) -> Result<Vec<(String, String)>> {
+    let known = &["last_path", "config_path", "last_scan", "disclaimer_accepted"];
+    let mut out = Vec::new();
+
+    let f = fs::File::open(path)?;
+    for line in BufReader::new(f).lines() {
+        let line = line?;
+        let trimmed = line.trim();
+        if trimmed.is_empty() || trimmed.starts_with('[') {
+            continue;
+        }
+        if let Some(eq) = trimmed.find('=') {
+            let key = trimmed[..eq].trim();
+            if !known.contains(&key) {
+                let val = trimmed[eq + 1..].trim();
+                out.push((key.to_string(), val.to_string()));
+            }
+        }
+    }
+    Ok(out)
+}

src/discovery.rs

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+//! Save-folder discovery.
+//!
+//! Traverses known path patterns across user profiles and common install
+//! locations to find Subnautica 2 save folders.
+
+use std::fs;
+use std::path::{Path, PathBuf};
+
+/// A discovered save folder.
+#[derive(Debug, Clone)]
+pub struct DiscoveredFolder {
+    pub label: String,
+    pub path: PathBuf,
+}
+
+/// Known save-root patterns (relative from a user profile or base directory).
+///
+/// The same patterns work on both platforms because UE5 keeps the same
+/// directory layout regardless of OS.
+const KNOWN_PATTERNS: &[(&str, &str)] = &[
+    ("Steam (LocalLow)", "AppData/LocalLow/Unknown Worlds/Subnautica2"),
+    ("Steam (LocalLow, alt)", "AppData/LocalLow/Unknown Worlds/Subnautica 2"),
+    ("AppData Local", "AppData/Local/Subnautica2/Saved/SaveGames"),
+    ("AppData Local (alt)", "AppData/Local/Subnautica 2/Saved/SaveGames"),
+    ("Xbox / Game Pass", "AppData/Local/Packages"), // partial — needs wildcard below
+    ("Saved Games", "Saved Games/Subnautica2"),
+    ("Saved Games (alt)", "Saved Games/Subnautica 2"),
+    ("Documents", "Documents/Subnautica2"),
+    ("Epic / Steam custom", "AppData/LocalLow/Subnautica2"),
+];
+
+/// Search all known locations for Subnautica 2 save folders.
+///
+/// Returns a deduplicated, ranked list.  The first result is cached as
+/// `last_path` in config.ini so subsequent launches skip the scan.
+pub fn discover_save_folders() -> Vec<DiscoveredFolder> {
+    let mut found: Vec<DiscoveredFolder> = Vec::new();
+    let mut seen: std::collections::HashSet<PathBuf> = std::collections::HashSet::new();
+
+    // 0. Fast-path: %LOCALAPPDATA%\Subnautica2\Saved\SaveGames (primary)
+    #[cfg(target_os = "windows")]
+    {
+        if let Some(local) = dirs::data_local_dir() {
+            let primary = local.join("Subnautica2").join("Saved").join("SaveGames");
+            if primary.exists() && has_save_files(&primary) {
+                found.push(DiscoveredFolder {
+                    label: "AppData Local".into(),
+                    path: primary,
+                });
+                return found;
+            }
+        }
+    }
+    #[cfg(not(target_os = "windows"))]
+    {
+        if let Some(data) = dirs::data_local_dir() {
+            let primary = data.join("Subnautica2").join("Saved").join("SaveGames");
+            if primary.exists() && has_save_files(&primary) {
+                found.push(DiscoveredFolder {
+                    label: "XDG Data".into(),
+                    path: primary,
+                });
+                return found;
+            }
+        }
+    }
+
+    // 1. Current user profile — remaining patterns
+    if let Some(home) = dirs::home_dir() {
+        for (label, rel) in KNOWN_PATTERNS {
+            let candidate = home.join(rel);
+            if candidate.exists() && candidate.is_dir() {
+                if has_save_files(&candidate) && seen.insert(candidate.clone()) {
+                    found.push(DiscoveredFolder {
+                        label: label.to_string(),
+                        path: candidate,
+                    });
+                }
+            }
+        }
+    }
+
+    // 2. Xbox / Game Pass wildcard scan
+    #[cfg(target_os = "windows")]
+    {
+        if let Some(home) = dirs::home_dir() {
+            let pkg_root = home.join("AppData/Local/Packages");
+            if pkg_root.exists() {
+                if let Ok(entries) = fs::read_dir(&pkg_root) {
+                    for entry in entries.flatten() {
+                        let name = entry.file_name();
+                        let name_str = name.to_string_lossy();
+                        if name_str.contains("Subnautica2") {
+                            let wgs = entry.path().join("SystemAppData/wgs");
+                            if wgs.exists() && has_save_files(&wgs) && seen.insert(wgs.clone()) {
+                                found.push(DiscoveredFolder {
+                                    label: "Xbox / Game Pass".into(),
+                                    path: wgs,
+                                });
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    // 3. Fallback: scan other user profiles
+    scan_other_users(&mut found, &mut seen);
+
+    // 4. Broad custom-install scan
+    scan_common_install_dirs(&mut found, &mut seen);
+
+    found
+}
+
+/// Check if a directory contains at least one `.sav` or `.save` file.
+fn has_save_files(dir: &Path) -> bool {
+    let check = |ext: &str| -> bool {
+        fs::read_dir(dir)
+            .map(|entries| {
+                entries.flatten().any(|e| {
+                    e.file_name()
+                        .to_string_lossy()
+                        .ends_with(ext)
+                })
+            })
+            .unwrap_or(false)
+    };
+    check(".sav") || check(".save")
+}
+
+/// Scan other user profiles on the system.
+#[cfg(target_os = "windows")]
+fn scan_other_users(
+    found: &mut Vec<DiscoveredFolder>,
+    seen: &mut std::collections::HashSet<PathBuf>,
+) {
+    for drive in fixed_drives() {
+        let users = Path::new(&drive).join("Users");
+        if !users.exists() {
+            continue;
+        }
+        if let Ok(entries) = fs::read_dir(&users) {
+            for user_dir in entries.flatten() {
+                let user_path = user_dir.path();
+                for (label, rel) in KNOWN_PATTERNS {
+                    let candidate = user_path.join(rel);
+                    if candidate.exists() && has_save_files(&candidate) && seen.insert(candidate.clone()) {
+                        found.push(DiscoveredFolder {
+                            label: label.to_string(),
+                            path: candidate,
+                        });
+                    }
+                }
+            }
+        }
+    }
+}
+
+#[cfg(not(target_os = "windows"))]
+fn scan_other_users(
+    found: &mut Vec<DiscoveredFolder>,
+    seen: &mut std::collections::HashSet<PathBuf>,
+) {
+    // On Linux, check /home for other users
+    let home_root = Path::new("/home");
+    if !home_root.exists() {
+        return;
+    }
+    if let Ok(entries) = fs::read_dir(home_root) {
+        for user_dir in entries.flatten() {
+            let user_path = user_dir.path();
+            for (label, rel) in KNOWN_PATTERNS {
+                let candidate = user_path.join(rel);
+                if candidate.exists() && has_save_files(&candidate) && seen.insert(candidate.clone()) {
+                    found.push(DiscoveredFolder {
+                        label: label.to_string(),
+                        path: candidate,
+                    });
+                }
+            }
+        }
+    }
+    // Also check common Steam Deck paths
+    let deck_paths = &[
+        Path::new("/run/media/mmcblk0p1/steamapps/compatdata"),
+        Path::new("/home/deck/.local/share/Steam/steamapps/compatdata"),
+    ];
+    for base in deck_paths {
+        if base.exists() {
+            // Walk compatdata for Subnautica 2 prefix
+            if let Ok(entries) = fs::read_dir(base) {
+                for app_entry in entries.flatten() {
+                    let pfx = app_entry.path().join("pfx/drive_c/users/steamuser");
+                    for (label, rel) in KNOWN_PATTERNS {
+                        let candidate = pfx.join(rel);
+                        if candidate.exists() && has_save_files(&candidate) && seen.insert(candidate.clone()) {
+                            found.push(DiscoveredFolder {
+                                label: format!("Steam Deck — {label}"),
+                                path: candidate,
+                            });
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+/// Scan common install directories (Program Files, Games, Steam, etc.).
+#[cfg(target_os = "windows")]
+fn scan_common_install_dirs(
+    found: &mut Vec<DiscoveredFolder>,
+    seen: &mut std::collections::HashSet<PathBuf>,
+) {
+    for drive in fixed_drives() {
+        let roots: &[&str] = &[
+            &format!("{drive}Games"),
+            &format!("{drive}Program Files"),
+            &format!("{drive}Program Files (x86)"),
+            &format!("{drive}Steam"),
+            &format!("{drive}Epic Games"),
+        ];
+        for rt in roots {
+            let p = Path::new(rt);
+            if !p.exists() {
+                continue;
+            }
+            walk_for_subnautica(p, "custom install", found, seen);
+        }
+    }
+}
+
+#[cfg(not(target_os = "windows"))]
+fn scan_common_install_dirs(
+    found: &mut Vec<DiscoveredFolder>,
+    seen: &mut std::collections::HashSet<PathBuf>,
+) {
+    let roots: &[&str] = &[
+        "/opt",
+        "/usr/local/games",
+        "/usr/share/games",
+    ];
+    for rt in roots {
+        let p = Path::new(rt);
+        if !p.exists() {
+            continue;
+        }
+        walk_for_subnautica(p, "custom install", found, seen);
+    }
+    // Steam library paths
+    if let Some(home) = dirs::home_dir() {
+        let steam = home.join(".local/share/Steam");
+        if steam.exists() {
+            walk_for_subnautica(&steam, "Steam", found, seen);
+        }
+    }
+}
+
+/// Recursively walk a root looking for folders named "*Subnautica*".
+fn walk_for_subnautica(
+    root: &Path,
+    label: &str,
+    found: &mut Vec<DiscoveredFolder>,
+    seen: &mut std::collections::HashSet<PathBuf>,
+) {
+    use std::collections::VecDeque;
+
+    let mut queue: VecDeque<PathBuf> = VecDeque::new();
+    queue.push_back(root.to_path_buf());
+
+    while let Some(dir) = queue.pop_front() {
+        // Limit depth: don't recurse more than 5 levels from root
+        let depth = dir.components().count().saturating_sub(root.components().count());
+        if depth > 5 {
+            continue;
+        }
+
+        let entries = match fs::read_dir(&dir) {
+            Ok(e) => e,
+            Err(_) => continue,
+        };
+
+        for entry in entries.flatten() {
+            let path = entry.path();
+            let name = path.file_name().map(|n| n.to_string_lossy().to_lowercase()).unwrap_or_default();
+
+            if name.contains("subnautica") {
+                if has_save_files(&path) && seen.insert(path.clone()) {
+                    found.push(DiscoveredFolder {
+                        label: label.to_string(),
+                        path: path.clone(),
+                    });
+                }
+            }
+
+            if path.is_dir() {
+                queue.push_back(path);
+            }
+        }
+    }
+}
+
+/// List available fixed drives on Windows.
+#[cfg(target_os = "windows")]
+fn fixed_drives() -> Vec<String> {
+    let mut drives = Vec::new();
+    for letter in b'A'..=b'Z' {
+        let path = format!("{}:\\", letter as char);
+        if Path::new(&path).exists() {
+            drives.push(path);
+        }
+    }
+    drives
+}
+
+// ── helpers for the TUI ──────────────────────────────────────────────────
+
+/// Validate that a manually entered path exists and contains save files.
+pub fn validate_custom_path(input: &str) -> Option<PathBuf> {
+    let expanded = if input.starts_with('~') {
+        if let Some(home) = dirs::home_dir() {
+            input.replacen('~', &home.to_string_lossy(), 1)
+        } else {
+            input.to_string()
+        }
+    } else {
+        input.to_string()
+    };
+    let path = PathBuf::from(expanded);
+    if path.exists() && has_save_files(&path) {
+        Some(path)
+    } else {
+        None
+    }
+}
+
+/// Derive the Config\Windows path from a SaveGames path.
+///
+/// Walks up to the `Saved` ancestor, then down to `Config/Windows`.
+pub fn derive_config_path(save_path: &Path) -> Option<PathBuf> {
+    let mut current = save_path.to_path_buf();
+
+    // Walk up looking for "Saved" component
+    loop {
+        if current.file_name().map(|n| n == "Saved").unwrap_or(false) {
+            let config = current.join("Config").join("Windows");
+            return if config.exists() { Some(config) } else { None };
+        }
+        if !current.pop() {
+            break;
+        }
+    }
+    None
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_derive_config_path_sample() {
+        // Should resolve from a save path even if dirs don't exist locally
+        let save = Path::new("C:/Users/test/AppData/Local/Subnautica2/Saved/SaveGames");
+        // Since we can't test existence, at least verify the walk logic compiles
+        let result = derive_config_path(save);
+        // On a test machine without the game, this returns None — which is fine
+        let _ = result;
+    }
+}

src/guard.rs

@@ -0,0 +1,104 @@
+//! Game-running guard and transaction logging.
+//!
+//! Before launch and before each destructive operation, check whether
+//! Subnautica 2 is running — the game holds file locks on `.sav` files
+//! while active.
+
+use anyhow::Result;
+use chrono::Local;
+use std::fs::{self, OpenOptions};
+use std::io::Write;
+use std::path::{Path, PathBuf};
+
+// ── process detection ──────────────────────────────────────────────────────
+
+/// Return `true` if Subnautica 2 appears to be running.
+#[cfg(target_os = "windows")]
+pub fn game_running() -> bool {
+    let out = std::process::Command::new("tasklist")
+        .args(["/FI", "IMAGENAME eq Subnautica2.exe", "/NH"])
+        .output();
+    match out {
+        Ok(o) => String::from_utf8_lossy(&o.stdout).contains("Subnautica2.exe"),
+        Err(_) => false,
+    }
+}
+
+#[cfg(not(target_os = "windows"))]
+pub fn game_running() -> bool {
+    let patterns = &["Subnautica2", "Subnautica2-Win64-Shipping"];
+    for pat in patterns {
+        if let Ok(out) = std::process::Command::new("pgrep")
+            .args(["-ci", pat])
+            .output()
+        {
+            let s = String::from_utf8_lossy(&out.stdout);
+            if let Ok(n) = s.trim().parse::<u32>() {
+                if n > 0 {
+                    return true;
+                }
+            }
+        }
+    }
+    false
+}
+
+// ── transaction logging ────────────────────────────────────────────────────
+
+/// Path to transaction.log next to the binary.
+pub fn log_path() -> PathBuf {
+    exe_dir().join("transaction.log")
+}
+
+fn exe_dir() -> PathBuf {
+    std::env::current_exe()
+        .ok()
+        .and_then(|p| p.parent().map(Path::to_path_buf))
+        .unwrap_or_else(|| PathBuf::from("."))
+}
+
+/// Maximum lines before rotation.
+const MAX_LOG_LINES: usize = 10_000;
+
+/// Append a timestamped log entry.  Auto-rotates if the log exceeds 10k lines.
+pub fn log_action(
+    action: &str,
+    detail: &str,
+    result: &str,
+    log_path: &Path,
+) -> Result<()> {
+    let stamp = Local::now().format("%Y-%m-%d %H:%M:%S");
+    let line = format!("{stamp} | {action:<8} | {detail} | {result}\n");
+
+    // Rotate if needed
+    if log_path.exists() {
+        if let Ok(content) = fs::read_to_string(log_path) {
+            let lines: Vec<&str> = content.lines().collect();
+            if lines.len() > MAX_LOG_LINES {
+                let keep: String = lines[lines.len() - MAX_LOG_LINES..].join("\n");
+                fs::write(log_path, keep + "\n").ok();
+            }
+        }
+    }
+
+    let mut f = OpenOptions::new()
+        .create(true)
+        .append(true)
+        .open(log_path)?;
+    f.write_all(line.as_bytes())?;
+    Ok(())
+}
+
+/// Check whether a path looks like a network/UNC path (for warning purposes).
+pub fn is_network_path(p: &str) -> bool {
+    p.starts_with("\\\\") || p.starts_with("//")
+}
+
+/// Estimate free space on the volume containing `path` in bytes.
+/// Returns `None` on platforms or filesystems where we can't determine this.
+pub fn available_space(_path: &Path) -> Option<u64> {
+    // Advisory only — the PowerShell original had a try/catch fallback.
+    // For a cross-platform build without platform-specific FFI, we
+    // return None and skip the disk-space warning.
+    None
+}

src/gvas.rs

@@ -0,0 +1,462 @@
+//! UE4/UE5 GVAS save-file binary parser.
+//!
+//! Ported from `legacy/extract_save_name.py`.  Extracts `SlotName` and
+//! `DisplayName` properties via manual binary walking, plus corruption
+//! detection by cross-referencing metadata against the canonical filename
+//! convention (`savegame_N.sav` / `savegame_N_M.bak`).
+
+use anyhow::{Context, Result};
+use std::fs;
+use std::path::Path;
+
+// ── low-level binary primitives ───────────────────────────────────────────
+
+/// Read a little-endian u32 at `offset`, returning `None` if out of bounds.
+fn read_u32(data: &[u8], offset: usize) -> Option<usize> {
+    if offset + 4 > data.len() {
+        return None;
+    }
+    Some(u32::from_le_bytes([
+        data[offset],
+        data[offset + 1],
+        data[offset + 2],
+        data[offset + 3],
+    ]) as usize)
+}
+
+/// Read a little-endian i32 at `offset`, returning `None` if out of bounds.
+fn read_i32(data: &[u8], offset: usize) -> Option<i64> {
+    if offset + 4 > data.len() {
+        return None;
+    }
+    Some(i32::from_le_bytes([
+        data[offset],
+        data[offset + 1],
+        data[offset + 2],
+        data[offset + 3],
+    ]) as i64)
+}
+
+/// Read a length-prefixed, null-terminated FName string.
+///
+/// Layout: `<u32 length><bytes><optional null>`
+/// Returns (string, new_offset) or (None, offset) on failure.
+fn read_fname(data: &[u8], offset: usize) -> (Option<String>, usize) {
+    let len = match read_u32(data, offset) {
+        Some(l) => l,
+        None => return (None, offset),
+    };
+    let mut off = offset + 4;
+    if len == 0 || off + len > data.len() {
+        return (None, off);
+    }
+    let mut raw = &data[off..off + len];
+    if raw.last() == Some(&0) {
+        raw = &raw[..raw.len() - 1];
+    }
+    off += len;
+    let s = String::from_utf8_lossy(raw).into_owned();
+    (Some(s), off)
+}
+
+/// Read an FString: length-prefixed, possibly UTF-16.
+///
+/// Layout: `<i32 length>` – negative means UTF-16 with `-len` chars,
+/// positive means UTF-8 byte count (including null terminator).
+/// Returns (string, new_offset).
+fn read_fstring(data: &[u8], offset: usize) -> (Option<String>, usize) {
+    let raw_len = match read_i32(data, offset) {
+        Some(l) => l,
+        None => return (None, offset),
+    };
+    let mut off = offset + 4;
+
+    if raw_len == 0 {
+        return (Some(String::new()), off);
+    }
+
+    let (bytes, is_utf16): (usize, bool) = if raw_len < 0 {
+        ((-raw_len) as usize * 2, true)
+    } else {
+        (raw_len as usize, false)
+    };
+
+    if off + bytes > data.len() {
+        return (None, off);
+    }
+
+    let mut raw = &data[off..off + bytes];
+    off += bytes;
+
+    let value = if is_utf16 {
+        // Decode UTF-16 LE
+        let code_units: Vec<u16> = raw
+            .chunks_exact(2)
+            .map(|c| u16::from_le_bytes([c[0], c[1]]))
+            .collect();
+        String::from_utf16_lossy(&code_units)
+    } else {
+        if raw.last() == Some(&0) {
+            raw = &raw[..raw.len() - 1];
+        }
+        String::from_utf8_lossy(raw).into_owned()
+    };
+
+    (Some(value), off)
+}
+
+// ── property extraction ────────────────────────────────────────────────────
+
+/// Find the first `StrProperty` named `prop_name` and return its FString value.
+///
+/// Walks the binary looking for the FName header of the property, then
+/// skips past the StrProperty metadata to read the string value.
+fn extract_str_property(data: &[u8], prop_name: &str) -> Result<String, String> {
+    let target = prop_name.as_bytes();
+    let mut offset = 0usize;
+    let mut attempts = 0u32;
+
+    while offset < data.len().saturating_sub(20) && attempts < 100 {
+        let found = match data[offset..]
+            .windows(target.len())
+            .position(|w| w == target)
+        {
+            Some(p) => offset + p,
+            None => return Err(format!("{prop_name} not found")),
+        };
+
+        // Each candidate must be a proper FName: preceded by a length dword
+        // matching the target length + 1 (null terminator), followed by a
+        // null byte.
+        if found < 4 {
+            offset = found + 1;
+            attempts += 1;
+            continue;
+        }
+
+        let name_len_field = read_u32(data, found - 4);
+        if name_len_field != Some(target.len() + 1) {
+            offset = found + 1;
+            attempts += 1;
+            continue;
+        }
+        if data[found + target.len()] != 0 {
+            offset = found + 1;
+            attempts += 1;
+            continue;
+        }
+
+        let after_name = found + target.len() + 1;
+        let (next_name, next_offset) = read_fname(data, after_name);
+        if next_name.as_deref() != Some("StrProperty") {
+            offset = found + 1;
+            attempts += 1;
+            continue;
+        }
+
+        // Skip StrProperty metadata: 9 bytes of property flags + padding,
+        // then the FString value.
+        let meta_offset = next_offset + 9;
+        if meta_offset + 4 > data.len() {
+            offset = found + 1;
+            attempts += 1;
+            continue;
+        }
+
+        let (value, _) = read_fstring(data, meta_offset);
+        match value {
+            Some(v) if !v.is_empty() && v.len() < 100 => return Ok(v),
+            _ => {
+                offset = found + 1;
+                attempts += 1;
+            }
+        }
+    }
+
+    Err(format!("no valid {prop_name}/StrProperty pair found"))
+}
+
+/// Find a BoolProperty by name and return its value (true/false).
+fn extract_bool_property(data: &[u8], prop_name: &str) -> Option<bool> {
+    let target = prop_name.as_bytes();
+    let mut offset = 0usize;
+    let mut attempts = 0u32;
+    while offset < data.len().saturating_sub(20) && attempts < 100 {
+        let found = data[offset..].windows(target.len()).position(|w| w == target);
+        let found = match found { Some(p) => offset + p, None => return None };
+        if found < 4 { offset = found + 1; attempts += 1; continue; }
+        let name_len_field = read_u32(data, found - 4);
+        if name_len_field != Some(target.len() + 1) { offset = found + 1; attempts += 1; continue; }
+        if data[found + target.len()] != 0 { offset = found + 1; attempts += 1; continue; }
+        let after_name = found + target.len() + 1;
+        let (next_name, next_offset) = read_fname(data, after_name);
+        if next_name.as_deref() != Some("BoolProperty") { offset = found + 1; attempts += 1; continue; }
+        let val_offset = next_offset + 9;
+        if val_offset >= data.len() { offset = found + 1; attempts += 1; continue; }
+        return Some(data[val_offset] != 0);
+    }
+    None
+}
+
+/// Find an IntProperty by name and return its u32 value.
+fn extract_int_property(data: &[u8], prop_name: &str) -> Option<u32> {
+    let target = prop_name.as_bytes();
+    let mut offset = 0usize;
+    let mut attempts = 0u32;
+    while offset < data.len().saturating_sub(20) && attempts < 100 {
+        let found = data[offset..].windows(target.len()).position(|w| w == target);
+        let found = match found { Some(p) => offset + p, None => return None };
+        if found < 4 { offset = found + 1; attempts += 1; continue; }
+        if read_u32(data, found - 4) != Some(target.len() + 1) { offset = found + 1; attempts += 1; continue; }
+        if data[found + target.len()] != 0 { offset = found + 1; attempts += 1; continue; }
+        let (next_name, next_offset) = read_fname(data, found + target.len() + 1);
+        if next_name.as_deref() != Some("IntProperty") { offset = found + 1; attempts += 1; continue; }
+        let val_offset = next_offset + 9;
+        if val_offset + 4 > data.len() { offset = found + 1; attempts += 1; continue; }
+        return read_u32(data, val_offset).map(|v| v as u32);
+    }
+    None
+}
+
+// ── public API ─────────────────────────────────────────────────────────────
+
+/// Full metadata from all known GVAS properties.
+#[derive(Debug, Clone, Default)]
+pub struct FullMetadata {
+    pub slot_name: Option<String>,
+    pub display_name: Option<String>,
+    pub is_online: bool,
+    pub was_multiplayer: bool,
+    pub game_mode: Option<String>,
+    pub level_name: Option<String>,
+    pub build_number: Option<u32>,
+    pub build_branch: Option<String>,
+    pub saves_count: Option<u32>,
+    pub latest_version: Option<u32>,
+    pub data_version: Option<u32>,
+}
+
+/// Parse a `.sav` or `.bak` file and return all known GVAS metadata.
+pub fn extract_full_metadata(path: &Path) -> Result<FullMetadata> {
+    let data = fs::read(path)
+        .with_context(|| format!("failed to read {}", path.display()))?;
+    Ok(FullMetadata {
+        slot_name: extract_str_property(&data, "SlotName").ok(),
+        display_name: extract_str_property(&data, "DisplayName").ok(),
+        is_online: extract_bool_property(&data, "bIsMultiplayerSave").unwrap_or(false),
+        was_multiplayer: extract_bool_property(&data, "bWasMultiplayerSave").unwrap_or(false),
+        game_mode: extract_str_property(&data, "GameMode").ok(),
+        level_name: extract_str_property(&data, "LevelName").ok(),
+        build_number: extract_int_property(&data, "BuildNumber"),
+        build_branch: extract_str_property(&data, "BuildBranch").ok(),
+        saves_count: extract_int_property(&data, "SavesCount"),
+        latest_version: extract_int_property(&data, "LatestVersion"),
+        data_version: extract_int_property(&data, "DataVersion"),
+    })
+}
+
+/// Extracted metadata from a GVAS save file.
+#[derive(Debug, Clone, Default)]
+pub struct SaveMetadata {
+    /// Internal slot name, e.g. "savegame_0"
+    pub slot_name: Option<String>,
+    /// Human-readable display name entered in-game
+    pub display_name: Option<String>,
+    /// Current online/multiplayer status (bIsMultiplayerSave)
+    pub is_online: bool,
+    /// Any extraction errors (non-fatal)
+    pub errors: Vec<String>,
+}
+
+/// Parse a `.sav` or `.bak` file and return its GVAS metadata.
+pub fn extract_metadata(path: &Path) -> Result<SaveMetadata> {
+    let data = fs::read(path)
+        .with_context(|| format!("failed to read {}", path.display()))?;
+
+    let mut errors = Vec::new();
+    let slot_name = match extract_str_property(&data, "SlotName") {
+        Ok(v) => Some(v),
+        Err(e) => {
+            errors.push(e);
+            None
+        }
+    };
+    let display_name = match extract_str_property(&data, "DisplayName") {
+        Ok(v) => Some(v),
+        Err(e) => {
+            errors.push(e);
+            None
+        }
+    };
+    let is_online = extract_bool_property(&data, "bIsMultiplayerSave").unwrap_or(false);
+
+    Ok(SaveMetadata {
+        slot_name,
+        display_name,
+        is_online,
+        errors,
+    })
+}
+
+// ── filename conventions ───────────────────────────────────────────────────
+
+/// Derive the expected slot name from a filename.
+///
+/// `savegame_2_9.sav` → `"savegame_2"`
+/// `savegame_0.bak`   → `"savegame_0"`
+/// `random.sav`       → `None`
+pub fn derive_slot_from_filename(filename: &str) -> Option<String> {
+    let re = regex::Regex::new(r"^(savegame_\d+)").ok()?;
+    re.captures(filename)
+        .and_then(|caps| caps.get(1))
+        .map(|m| m.as_str().to_string())
+}
+
+/// Return a corruption reason, or `None` if the file looks clean.
+pub fn corruption_check(filename: &str, slot_name: Option<&str>) -> Option<String> {
+    let expected_slot = derive_slot_from_filename(filename);
+
+    if expected_slot.is_none() {
+        return Some("nonstandard filename".into());
+    }
+
+    let expected = expected_slot.unwrap();
+
+    if let Some(sn) = slot_name {
+        if sn != expected {
+            return Some(format!("slot mismatch ({sn})"));
+        }
+    }
+
+    // Non-canonical .sav: savegame_N_M.sav is not a live file
+    if filename.ends_with(".sav") {
+        let re = regex::Regex::new(r"^savegame_\d+\.sav$").ok()?;
+        if !re.is_match(filename) {
+            return Some("non-canonical .sav".into());
+        }
+    }
+
+    None
+}
+
+// ── tests ──────────────────────────────────────────────────────────────────
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_derive_slot() {
+        assert_eq!(
+            derive_slot_from_filename("savegame_0.sav"),
+            Some("savegame_0".into())
+        );
+        assert_eq!(
+            derive_slot_from_filename("savegame_2_9.bak"),
+            Some("savegame_2".into())
+        );
+        assert_eq!(
+            derive_slot_from_filename("savegame_0.bak"),
+            Some("savegame_0".into())
+        );
+        assert_eq!(derive_slot_from_filename("random.sav"), None);
+    }
+
+    #[test]
+    fn test_corruption_check() {
+        // Canonical live file
+        assert_eq!(
+            corruption_check("savegame_0.sav", Some("savegame_0")),
+            None
+        );
+        // Versioned .sav is non-canonical
+        assert_eq!(
+            corruption_check("savegame_0_9.sav", Some("savegame_0")),
+            Some("non-canonical .sav".into())
+        );
+        // Slot mismatch
+        assert_eq!(
+            corruption_check("savegame_1.bak", Some("savegame_0")),
+            Some("slot mismatch (savegame_0)".into())
+        );
+        // Backup that matches
+        assert_eq!(
+            corruption_check("savegame_2_5.bak", Some("savegame_2")),
+            None
+        );
+    }
+
+    #[test]
+    fn dump_all_samples() {
+        use chrono::TimeZone;
+        let dir = std::path::Path::new("samples");
+        let Ok(entries) = std::fs::read_dir(dir) else { return };
+        let mut files: Vec<_> = entries
+            .filter_map(|e| e.ok())
+            .filter(|e| {
+                let n = e.file_name();
+                let s = n.to_string_lossy();
+                s.ends_with(".sav") || s.ends_with(".bak")
+            })
+            .collect();
+        // Sort by slot (extracted from filename), then mtime desc
+        files.sort_by(|a, b| {
+            use crate::gvas::derive_slot_from_filename;
+            let sa = derive_slot_from_filename(&a.file_name().to_string_lossy());
+            let sb = derive_slot_from_filename(&b.file_name().to_string_lossy());
+            let ma = a.metadata().ok().and_then(|m| m.modified().ok());
+            let mb = b.metadata().ok().and_then(|m| m.modified().ok());
+            sa.cmp(&sb).then_with(|| mb.cmp(&ma))
+        });
+        println!("\n{:<8} {:<26} {:<6} {:>7}  {:<19}  {:<28}", "", "Display Name", "Type", "Size", "Date", "File");
+        println!("{}", "-".repeat(115));
+        let mut seen = std::collections::HashSet::new();
+        for entry in &files {
+            let path = entry.path();
+            let name = entry.file_name().to_string_lossy().to_string();
+            let size = entry.metadata().map(|m| m.len()).unwrap_or(0);
+            let mtime = entry.metadata().ok().and_then(|m| m.modified().ok())
+                .and_then(|t| { let s = t.duration_since(std::time::UNIX_EPOCH).ok()?.as_secs(); chrono::Local.timestamp_opt(s as i64,0).single() })
+                .map(|dt| dt.format("%Y-%m-%d %H:%M:%S").to_string());
+            let meta = extract_metadata(&path).ok();
+            let slot = meta.as_ref().and_then(|m| m.slot_name.clone())
+                .unwrap_or_else(|| derive_slot_from_filename(&name).unwrap_or_else(|| "?".into()));
+            let display = meta.as_ref().and_then(|m| m.display_name.clone()).unwrap_or_else(|| "(unnamed)".into());
+            let online = meta.map(|m| m.is_online).unwrap_or(false);
+            let num = slot.strip_prefix("savegame_").unwrap_or(&slot);
+            let first = seen.insert(slot.clone());
+            let label = if first { format!("Slot {num}") } else { String::new() };
+            let typ = if online { "Online" } else { "Local" };
+            let sz = if size < 1024 { format!("{size} B") } else if size < 1_048_576 { format!("{:.0} KB", size as f64 / 1024.0) } else { format!("{:.1} MB", size as f64 / 1_048_576.0) };
+            println!("{label:<8} {display:<26} {typ:<6} {sz:>7}  {:<19}  {name:<28}", mtime.as_deref().unwrap_or("?"));
+        }
+        println!();
+    }
+
+    #[test]
+    fn print_full_meta() {
+        let p = Path::new("samples/savegame_1.sav");
+        if !p.exists() { return; }
+        let m = extract_full_metadata(p).unwrap();
+        println!("slot: {:?}", m.slot_name);
+        println!("display: {:?}", m.display_name);
+        println!("online: {}", m.is_online);
+        println!("was_multi: {}", m.was_multiplayer);
+        println!("gamemode: {:?}", m.game_mode);
+        println!("level: {:?}", m.level_name);
+        println!("build: {:?}", m.build_number);
+        println!("branch: {:?}", m.build_branch);
+        println!("savescnt: {:?}", m.saves_count);
+        println!("latest: {:?}", m.latest_version);
+        println!("dataver: {:?}", m.data_version);
+    }
+
+    #[test]
+    fn test_real_sample() {
+        let p = Path::new("samples/savegame_0.sav");
+        if p.exists() {
+            let meta = extract_metadata(p).unwrap();
+            assert!(meta.slot_name.is_some() || !meta.errors.is_empty());
+        }
+    }
+}

src/ops.rs

@@ -0,0 +1,530 @@
+//! File operations: recover .bak→.sav, backup/restore full, .ini management.
+//!
+//! The `.bak` recovery bug from the PowerShell script is fixed here:
+//! versioned backups (`savegame_0_9.bak`) recover to the canonical
+//! `savegame_0.sav`, not `savegame_0_9.sav`.
+
+use crate::gvas::{derive_slot_from_filename, extract_metadata};
+use anyhow::{Context, Result};
+use chrono::Local;
+use std::fs;
+use std::path::{Path, PathBuf};
+
+// ── public operation types ─────────────────────────────────────────────────
+
+/// Result of a backup operation.
+#[derive(Debug, Clone)]
+pub struct BackupResult {
+    pub files_copied: usize,
+    pub total_size: u64,
+    pub dest_dir: PathBuf,
+    pub verified: bool,
+}
+
+/// Result of a recovery operation.
+#[derive(Debug, Clone)]
+pub struct RecoveryResult {
+    pub source: String,
+    pub target: String,
+    pub old_saved_as: Option<String>,
+}
+
+// ── .sav recovery from .bak ────────────────────────────────────────────────
+
+/// Restore a `.sav` file from a `.bak` backup.
+///
+/// The target is derived from the canonical slot name (e.g.
+/// `savegame_0_9.bak` → `savegame_0.sav`).  If a live `.sav` exists,
+/// it is renamed to `<target>.old` as a rollback safety net before
+/// the backup is copied in.
+pub fn recover_bak_to_sav(
+    save_folder: &Path,
+    bak_filename: &str,
+) -> Result<RecoveryResult> {
+    let bak_path = save_folder.join(bak_filename);
+
+    if !bak_path.exists() {
+        anyhow::bail!("backup file not found: {}", bak_path.display());
+    }
+
+    // Sanity: reject tiny files (< 1 KB)
+    let meta = fs::metadata(&bak_path)
+        .with_context(|| format!("cannot read {}", bak_path.display()))?;
+    if meta.len() < 1024 {
+        anyhow::bail!(
+            "backup file too small ({} bytes) — aborting restore",
+            meta.len()
+        );
+    }
+
+    // Derive the canonical .sav target
+    let slot = derive_slot_from_filename(bak_filename)
+        .ok_or_else(|| anyhow::anyhow!("cannot derive slot from filename: {bak_filename}"))?;
+    let target_name = format!("{slot}.sav");
+    let target_path = save_folder.join(&target_name);
+
+    let mut old_saved_as = None;
+
+    // Roll the existing .sav aside
+    if target_path.exists() {
+        let old_path = save_folder.join(format!("{target_name}.old"));
+        fs::rename(&target_path, &old_path)
+            .with_context(|| format!("cannot rename {} → {}", target_path.display(), old_path.display()))?;
+        old_saved_as = Some(format!("{target_name}.old"));
+    }
+
+    // Copy .bak → .sav
+    fs::copy(&bak_path, &target_path).with_context(|| {
+        format!(
+            "cannot copy {} → {}",
+            bak_path.display(),
+            target_path.display()
+        )
+    })?;
+
+    Ok(RecoveryResult {
+        source: bak_filename.to_string(),
+        target: target_name,
+        old_saved_as,
+    })
+}
+
+// ── full backup ────────────────────────────────────────────────────────────
+
+/// Create a full backup of the save folder to `NotAlterra_Backups/notalterra_copy_<timestamp>`.
+pub fn create_full_backup(
+    save_folder: &Path,
+    backup_root: &Path,
+) -> Result<BackupResult> {
+    let ts = Local::now().format("%Y-%m-%d_%H%M%S");
+    let dest = backup_root.join(format!("notalterra_copy_{ts}"));
+
+    fs::create_dir_all(&dest)
+        .with_context(|| format!("cannot create backup dir {}", dest.display()))?;
+
+    let mut copied = 0usize;
+    let mut total = 0u64;
+
+    if let Err(e) = copy_save_files(save_folder, &dest, &mut copied, &mut total) {
+        let _ = fs::remove_dir_all(&dest);
+        return Err(e);
+    }
+
+    // Verify
+    let verified = verify_backup(save_folder, &dest);
+
+    Ok(BackupResult {
+        files_copied: copied,
+        total_size: total,
+        dest_dir: dest,
+        verified,
+    })
+}
+
+/// Restore a full backup into the save folder.
+///
+/// Creates a pre-restore safety backup first.
+pub fn restore_full_backup(
+    backup_dir: &Path,
+    save_folder: &Path,
+    backup_root: &Path,
+) -> Result<()> {
+    // Pre-restore safety backup
+    let ts = Local::now().format("%Y-%m-%d_%H%M%S");
+    let pre_restore = backup_root.join(format!("pre_restore_{ts}"));
+    fs::create_dir_all(&pre_restore)
+        .with_context(|| format!("cannot create pre-restore dir {}", pre_restore.display()))?;
+    let mut dummy = 0usize;
+    let mut dummy_size = 0u64;
+    if copy_save_files(save_folder, &pre_restore, &mut dummy, &mut dummy_size).is_err() {
+        let _ = fs::remove_dir_all(&pre_restore);
+    }
+
+    // Overwrite save folder with backup
+    copy_save_files(backup_dir, save_folder, &mut dummy, &mut dummy_size)?;
+
+    Ok(())
+}
+
+// ── .ini management ────────────────────────────────────────────────────────
+
+/// Back up .ini files from the Config\Windows folder.
+pub fn backup_ini_files(config_path: &Path, backup_root: &Path) -> Result<BackupResult> {
+    let ini_files: Vec<PathBuf> = fs::read_dir(config_path)
+        .with_context(|| format!("cannot read {}", config_path.display()))?
+        .flatten()
+        .filter(|e| {
+            e.file_name()
+                .to_string_lossy()
+                .ends_with(".ini")
+        })
+        .map(|e| e.path())
+        .collect();
+
+    if ini_files.is_empty() {
+        anyhow::bail!("no .ini files found in {}", config_path.display());
+    }
+
+    let ts = Local::now().format("%Y-%m-%d_%H%M%S");
+    let dest = backup_root.join(format!("ini_backup_{ts}"));
+
+    fs::create_dir_all(&dest)
+        .with_context(|| format!("cannot create ini backup dir {}", dest.display()))?;
+
+    let mut copied = 0usize;
+    let mut total = 0u64;
+
+    for f in &ini_files {
+        let meta = fs::metadata(f)?;
+        total += meta.len();
+        let name = f.file_name().unwrap();
+        fs::copy(f, dest.join(name))?;
+        copied += 1;
+    }
+
+    let verified = verify_backup(config_path, &dest);
+
+    Ok(BackupResult {
+        files_copied: copied,
+        total_size: total,
+        dest_dir: dest,
+        verified,
+    })
+}
+
+/// Restore .ini files from a backup into the Config\Windows folder.
+pub fn restore_ini_files(
+    backup_dir: &Path,
+    config_path: &Path,
+    backup_root: &Path,
+) -> Result<()> {
+    // Pre-restore safety
+    let ts = Local::now().format("%Y-%m-%d_%H%M%S");
+    let pre_restore = backup_root.join(format!("ini_pre_restore_{ts}"));
+    fs::create_dir_all(&pre_restore)?;
+
+    // Back up current .ini files
+    if let Ok(entries) = fs::read_dir(config_path) {
+        for entry in entries.flatten() {
+            let name = entry.file_name();
+            if name.to_string_lossy().ends_with(".ini") {
+                fs::copy(entry.path(), pre_restore.join(&name)).ok();
+            }
+        }
+    }
+
+    // Copy all files from backup → config_path
+    for entry in fs::read_dir(backup_dir)? {
+        let entry = entry?;
+        fs::copy(entry.path(), config_path.join(entry.file_name()))?;
+    }
+
+    Ok(())
+}
+
+/// Delete all .ini files from the Config\Windows folder.
+///
+/// **Guarded**: refuses to delete unless at least one `ini_backup_*` exists
+/// in the backup root.
+pub fn delete_ini_files(config_path: &Path, backup_root: &Path) -> Result<usize> {
+    // Guard: check for existing backup
+    let has_backup = backup_root.exists()
+        && fs::read_dir(backup_root)
+            .map(|entries| {
+                entries.flatten().any(|e| {
+                    e.file_name()
+                        .to_string_lossy()
+                        .starts_with("ini_backup_")
+                })
+            })
+            .unwrap_or(false);
+
+    if !has_backup {
+        anyhow::bail!(
+            "no .ini backup found — create a backup first via 'Manage Config > Backup'"
+        );
+    }
+
+    let mut deleted = 0usize;
+    for entry in fs::read_dir(config_path)? {
+        let entry = entry?;
+        if entry.file_name().to_string_lossy().ends_with(".ini") {
+            fs::remove_file(entry.path())?;
+            deleted += 1;
+        }
+    }
+
+    Ok(deleted)
+}
+
+/// List existing full backups in the backup root.
+pub fn list_full_backups(backup_root: &Path) -> Vec<PathBuf> {
+    list_subdirs(backup_root, "notalterra_copy_")
+}
+
+/// List existing .ini backups in the backup root.
+pub fn list_ini_backups(backup_root: &Path) -> Vec<PathBuf> {
+    list_subdirs(backup_root, "ini_backup_")
+}
+
+/// List .bak files in a save folder, sorted by mtime descending.
+pub fn list_bak_files(save_folder: &Path) -> Vec<PathBuf> {
+    let mut files: Vec<PathBuf> = fs::read_dir(save_folder)
+        .into_iter()
+        .flatten()
+        .flatten()
+        .filter(|e| {
+            e.file_name()
+                .to_string_lossy()
+                .ends_with(".bak")
+        })
+        .map(|e| e.path())
+        .collect();
+
+    // Sort by mtime descending
+    files.sort_by(|a, b| {
+        let ma = fs::metadata(a).ok();
+        let mb = fs::metadata(b).ok();
+        match (ma.and_then(|m| m.modified().ok()), mb.and_then(|m| m.modified().ok())) {
+            (Some(a), Some(b)) => b.cmp(&a),
+            _ => std::cmp::Ordering::Equal,
+        }
+    });
+
+    files
+}
+
+/// Enriched .bak file entry with GVAS metadata for the picker UI.
+#[derive(Debug, Clone)]
+pub struct BakFileSummary {
+    pub path: PathBuf,
+    pub filename: String,
+    pub slot: String,
+    pub display_name: Option<String>,
+    pub is_online: bool,
+    pub size: u64,
+    pub mtime: Option<String>,
+}
+
+/// List .bak files with parsed GVAS metadata.
+///
+/// Each file is read to extract `SlotName` and `DisplayName`.  Files that
+/// fail to parse still appear — the metadata fields are simply empty.
+pub fn list_bak_files_with_meta(save_folder: &Path) -> Vec<BakFileSummary> {
+    use chrono::TimeZone;
+
+    let mut files: Vec<BakFileSummary> = Vec::new();
+
+    let entries: Vec<_> = fs::read_dir(save_folder)
+        .into_iter()
+        .flatten()
+        .flatten()
+        .filter(|e| {
+            e.file_name()
+                .to_string_lossy()
+                .ends_with(".bak")
+        })
+        .collect();
+
+    for entry in entries {
+        let path = entry.path();
+        let filename = entry.file_name().to_string_lossy().to_string();
+
+        let meta = fs::metadata(&path).ok();
+        let size = meta.as_ref().map(|m| m.len()).unwrap_or(0);
+        let mtime = meta
+            .as_ref()
+            .and_then(|m| m.modified().ok())
+            .and_then(|t| {
+                let secs = t
+                    .duration_since(std::time::UNIX_EPOCH)
+                    .ok()?
+                    .as_secs();
+                Local
+                    .timestamp_opt(secs as i64, 0)
+                    .single()
+                    .map(|dt| dt.format("%Y-%m-%d %H:%M").to_string())
+            });
+
+        // Use filename-derived slot for grouping (authoritative).
+        // Internal SlotName is advisory — files may have been moved.
+        let slot = derive_slot_from_filename(&filename).unwrap_or_else(|| "?".into());
+        let meta = extract_metadata(&path).ok();
+        let display_name = meta.as_ref().and_then(|m| m.display_name.clone());
+        let is_online = meta.as_ref().map(|m| m.is_online).unwrap_or(false);
+
+        files.push(BakFileSummary {
+            path,
+            filename,
+            slot,
+            display_name,
+            is_online,
+            size,
+            mtime,
+        });
+    }
+
+    // Sort by mtime descending, then by slot
+    files.sort_by(|a, b| {
+        a.slot
+            .cmp(&b.slot)
+            .then_with(|| b.mtime.cmp(&a.mtime))
+    });
+
+    files
+}
+
+/// Keep only the most recent .bak per slot, discarding older versioned backups.
+pub fn dedup_by_slot(files: Vec<BakFileSummary>) -> Vec<BakFileSummary> {
+    let mut seen: std::collections::HashSet<String> = std::collections::HashSet::new();
+    let mut out = Vec::new();
+    for f in files {
+        if seen.insert(f.slot.clone()) {
+            out.push(f);
+        }
+    }
+    out
+}
+
+/// Scan the save folder and return stats for the dashboard.
+pub fn folder_stats(
+    save_folder: Option<&Path>,
+    backup_root: &Path,
+) -> (usize, usize, bool) {
+    let (live, bak) = if let Some(dir) = save_folder {
+        if let Ok(entries) = fs::read_dir(dir) {
+            let mut l = 0;
+            let mut b = 0;
+            for e in entries.flatten() {
+                let name = e.file_name();
+                let name_str = name.to_string_lossy();
+                if name_str.ends_with(".sav") {
+                    l += 1;
+                } else if name_str.ends_with(".bak") {
+                    b += 1;
+                }
+            }
+            (l, b)
+        } else {
+            (0, 0)
+        }
+    } else {
+        (0, 0)
+    };
+
+    let ini = backup_root.exists()
+        && fs::read_dir(backup_root)
+            .map(|entries| {
+                entries.flatten().any(|e| {
+                    e.file_name()
+                        .to_string_lossy()
+                        .starts_with("ini_backup_")
+                })
+            })
+            .unwrap_or(false);
+
+    (live, bak, ini)
+}
+
+// ── internal helpers ───────────────────────────────────────────────────────
+
+/// Copy only files matching `savegame_*` prefix from `src` to `dest`.
+fn copy_save_files(
+    src: &Path,
+    dest: &Path,
+    count: &mut usize,
+    total_size: &mut u64,
+) -> Result<()> {
+    fs::create_dir_all(dest)?;
+    for entry in fs::read_dir(src)? {
+        let entry = entry?;
+        let name = entry.file_name();
+        let name_str = name.to_string_lossy();
+        let meta = entry.metadata()?;
+        if meta.is_dir() {
+            continue;
+        }
+        if meta.is_file() && name_str.starts_with("savegame_") {
+            let dest_path = dest.join(&name);
+            fs::copy(&entry.path(), &dest_path)?;
+            *count += 1;
+            *total_size += meta.len();
+        }
+    }
+    Ok(())
+}
+
+fn copy_recursive(
+    src: &Path,
+    dest: &Path,
+    count: &mut usize,
+    total_size: &mut u64,
+) -> Result<()> {
+    fs::create_dir_all(dest)?;
+
+    for entry in fs::read_dir(src)? {
+        let entry = entry?;
+        let src_path = entry.path();
+        let name = entry.file_name();
+        let dest_path = dest.join(&name);
+
+        let meta = entry.metadata()?;
+        if meta.is_dir() {
+            copy_recursive(&src_path, &dest_path, count, total_size)?;
+        } else if meta.is_file() {
+            fs::copy(&src_path, &dest_path)?;
+            *count += 1;
+            *total_size += meta.len();
+        }
+    }
+    Ok(())
+}
+
+/// Verify that files in `src` match those in `dest` (by relative path + size).
+fn verify_backup(src: &Path, dest: &Path) -> bool {
+    let Ok(src_entries) = fs::read_dir(src) else { return false };
+    for entry in src_entries.flatten() {
+        let name = entry.file_name();
+        let name_str = name.to_string_lossy();
+        if !name_str.starts_with("savegame_") {
+            continue;
+        }
+        let expected = dest.join(&name);
+        if !expected.exists() {
+            return false;
+        }
+        if let (Ok(sm), Ok(dm)) = (entry.metadata(), fs::metadata(&expected)) {
+            if sm.len() != dm.len() {
+                return false;
+            }
+        }
+    }
+    true
+}
+
+fn list_subdirs(root: &Path, prefix: &str) -> Vec<PathBuf> {
+    if !root.exists() {
+        return Vec::new();
+    }
+    let mut dirs: Vec<PathBuf> = fs::read_dir(root)
+        .into_iter()
+        .flatten()
+        .flatten()
+        .filter(|e| {
+            e.file_name()
+                .to_string_lossy()
+                .starts_with(prefix)
+                && e.path().is_dir()
+        })
+        .map(|e| e.path())
+        .collect();
+    dirs.sort_by(|a, b| {
+        let ma = fs::metadata(a).map(|m| m.modified().ok()).ok().flatten();
+        let mb = fs::metadata(b).map(|m| m.modified().ok()).ok().flatten();
+        match (ma, mb) {
+            (Some(a), Some(b)) => b.cmp(&a),
+            _ => std::cmp::Ordering::Equal,
+        }
+    });
+    dirs
+}

src/tui.rs

@@ -0,0 +1,675 @@
+//! Modern terminal UI built on ratatui + crossterm.
+//!
+//! Design principles:
+//! - Dashboard layout: header bar, main panel, status line
+//! - Keyboard-first: arrow keys + Enter/Esc, no mouse dependency
+//! - Semantic color: cyan=info, green=success, yellow=warning, red=error
+//! - Adapts to terminal size; minimum 60×15
+
+use ratatui::{
+    layout::{Alignment, Constraint, Direction, Layout, Rect},
+    style::{Color, Modifier, Style},
+    text::{Line, Span},
+    widgets::{Block, BorderType, Borders, Clear, List, ListItem, ListState, Paragraph},
+    Frame,
+};
+use std::time::Instant;
+
+// ── app state ──────────────────────────────────────────────────────────────
+
+/// Global application state passed through every frame.
+pub struct AppState {
+    /// Terminal dimensions (updated on Resize events)
+    pub cols: u16,
+    pub rows: u16,
+    /// Current save-folder path (for the header bar)
+    pub save_path: Option<String>,
+    /// Number of live .sav files in the current folder
+    pub live_save_count: usize,
+    /// Number of .bak backup files
+    pub backup_count: usize,
+    /// Whether a .ini backup exists
+    pub has_ini_backup: bool,
+    /// Version string for the header
+    pub version: String,
+    /// Last operation result (for the status bar)
+    pub status_message: Option<String>,
+    pub status_style: StatusStyle,
+    /// Spinner state
+    pub spinner_active: bool,
+    pub spinner_start: Option<Instant>,
+}
+
+#[derive(Clone, Copy, PartialEq)]
+pub enum StatusStyle {
+    Info,
+    Success,
+    Warning,
+    Error,
+    Neutral,
+}
+
+impl Default for AppState {
+    fn default() -> Self {
+        Self {
+            cols: 80,
+            rows: 24,
+            save_path: None,
+            live_save_count: 0,
+            backup_count: 0,
+            has_ini_backup: false,
+            version: String::new(),
+            status_message: None,
+            status_style: StatusStyle::Neutral,
+            spinner_active: false,
+            spinner_start: None,
+        }
+    }
+}
+
+// ── public rendering entry points ──────────────────────────────────────────
+
+/// Draw the main menu.  Hides the locate item when saves are already found.
+pub fn draw_main_menu(f: &mut Frame, state: &mut ListState, app: &AppState, save_found: bool) {
+    let items: Vec<&str> = if save_found {
+        vec![
+            "  Recover .sav file from .bak",
+            "  Create full backup",
+            "  Restore full backup",
+            "  Inspect save files",
+            "  Manage UE5 Config (.ini) files",
+            "  View disclaimer",
+            "  Exit",
+        ]
+    } else {
+        vec![
+            "  Locate Subnautica save files",
+            "  Recover .sav file from .bak",
+            "  Create full backup",
+            "  Restore full backup",
+            "  Inspect save files",
+            "  Manage UE5 Config (.ini) files",
+            "  View disclaimer",
+            "  Exit",
+        ]
+    };
+    let descs: Vec<&str> = if save_found {
+        vec![
+            "Restore a .sav file from its .bak backup",
+            "Copy the savegame files to NotAlterra_Backups",
+            "Restore a full backup from NotAlterra_Backups",
+            "View detailed GVAS metadata for each save file",
+            "Backup, restore, or delete .ini files in Config/Windows",
+            "Re-read the disclaimer and terms of use",
+            "Close NotAlterra",
+        ]
+    } else {
+        vec![
+            "Scan all drives for Subnautica 2 save folders",
+            "Restore a .sav file from its .bak backup",
+            "Copy the savegame files to NotAlterra_Backups",
+            "Restore a full backup from NotAlterra_Backups",
+            "View detailed GVAS metadata for each save file",
+            "Backup, restore, or delete .ini files in Config/Windows",
+            "Re-read the disclaimer and terms of use",
+            "Close NotAlterra",
+        ]
+    };
+    let chunks = standard_layout(f.area(), items.len());
+
+    draw_header(f, chunks[0], app);
+    draw_status_dashboard(f, chunks[1], app);
+
+    let prompt = "↑/↓ navigate  Enter select";
+    draw_select_list(f, chunks[2], &items, &descs, prompt, state);
+    draw_status_bar(f, chunks[3], app);
+}
+
+/// Draw the disclaimer popup with full warning text.
+pub fn draw_disclaimer_popup(f: &mut Frame, _app: &AppState, selected_yes: bool) {
+    let popup_w = 60.min(f.area().width.saturating_sub(4));
+    let popup_h = 18.min(f.area().height.saturating_sub(4));
+    let area = centered_rect_size(popup_w, popup_h, f.area());
+    f.render_widget(Clear, area);
+
+    let block = Block::default()
+        .borders(Borders::ALL)
+        .border_type(BorderType::Plain)
+        .border_style(Style::default().fg(Color::Yellow));
+    f.render_widget(block, area);
+
+    let inner = inner(area, 2, 1);
+
+    let lines = vec![
+        Line::from(Span::styled("DISCLAIMER", Style::default().fg(Color::Yellow).add_modifier(Modifier::BOLD))),
+        Line::from(""),
+        Line::from(Span::styled("This tool was created using an AI Agent. While", Style::default().fg(Color::White))),
+        Line::from(Span::styled("every effort has been made to ensure it works", Style::default().fg(Color::White))),
+        Line::from(Span::styled("correctly, you should review the code and test", Style::default().fg(Color::White))),
+        Line::from(Span::styled("on a backup before using it on live save files.", Style::default().fg(Color::White))),
+        Line::from(""),
+        Line::from(Span::styled("NotAlterra is not affiliated with Unknown Worlds", Style::default().fg(Color::DarkGray))),
+        Line::from(Span::styled("Entertainment or KRAFTON. Use at your own risk.", Style::default().fg(Color::DarkGray))),
+        Line::from(""),
+        Line::from(Span::styled("The author is NOT responsible for any data loss.", Style::default().fg(Color::White).add_modifier(Modifier::BOLD))),
+    ];
+    f.render_widget(Paragraph::new(lines).alignment(Alignment::Center), Rect { height: 11, ..inner });
+
+    let yes_style = if selected_yes { Style::default().fg(Color::Black).bg(Color::Green).add_modifier(Modifier::BOLD) } else { Style::default().fg(Color::Green) };
+    let no_style = if !selected_yes { Style::default().fg(Color::Black).bg(Color::Red).add_modifier(Modifier::BOLD) } else { Style::default().fg(Color::Red) };
+    let buttons = Line::from(vec![Span::styled("[ Accept ]", yes_style), Span::raw("    "), Span::styled("[ Decline ]", no_style)]);
+    f.render_widget(Paragraph::new(buttons).alignment(Alignment::Center), Rect { y: inner.y + 12, height: 1, ..inner });
+}
+
+/// Draw a simple confirmation popup with [ Yes ] [ No ] buttons.
+pub fn draw_confirm_popup(
+    f: &mut Frame,
+    _app: &AppState,
+    title: &str,
+    details: &[(&str, &str)],
+    selected_yes: bool,
+) {
+    let max_w = details.iter().map(|(k, v)| k.len() + v.len() + 4).max().unwrap_or(20).max(30) as u16;
+    let popup_w = (max_w + 4).min(f.area().width.saturating_sub(4));
+    let popup_h = (details.len() as u16 + 6).min(f.area().height.saturating_sub(4));
+    let area = centered_rect_size(popup_w, popup_h, f.area());
+    f.render_widget(Clear, area);
+
+    let block = Block::default()
+        .borders(Borders::ALL)
+        .border_type(BorderType::Plain)
+        .border_style(Style::default().fg(Color::Yellow));
+    f.render_widget(block, area);
+
+    let inner = inner(area, 2, 1);
+
+    // Title
+    f.render_widget(
+        Paragraph::new(Span::styled(title, Style::default().fg(Color::Yellow).add_modifier(Modifier::BOLD)))
+            .alignment(Alignment::Center),
+        Rect { height: 1, ..inner },
+    );
+
+    // Details
+    let detail_lines: Vec<Line> = details.iter().map(|(k, v)| {
+        let icon = if k.starts_with('⚠') { Color::Yellow } else { Color::Gray };
+        Line::from(vec![
+            Span::styled(format!("{k}: "), Style::default().fg(icon)),
+            Span::styled(*v, Style::default()),
+        ])
+    }).collect();
+    f.render_widget(
+        Paragraph::new(detail_lines),
+        Rect { y: inner.y + 2, height: details.len() as u16, ..inner },
+    );
+
+    // Yes / No buttons
+    let yes_style = if selected_yes { Style::default().fg(Color::Black).bg(Color::Green).add_modifier(Modifier::BOLD) }
+        else { Style::default().fg(Color::Green) };
+    let no_style = if !selected_yes { Style::default().fg(Color::Black).bg(Color::Red).add_modifier(Modifier::BOLD) }
+        else { Style::default().fg(Color::Red) };
+    let buttons = Line::from(vec![
+        Span::styled("[ Yes ]", yes_style),
+        Span::raw("    "),
+        Span::styled("[ No ]", no_style),
+    ]);
+    f.render_widget(
+        Paragraph::new(buttons).alignment(Alignment::Center),
+        Rect { y: inner.y + inner.height.saturating_sub(1), height: 1, ..inner },
+    );
+}
+
+pub fn draw_ok_dialog(f: &mut Frame, _app: &AppState, title: &str, message: &str) {
+    let content_w = message.lines().map(|l| l.len()).max().unwrap_or(20).max(title.len()) as u16 + 6;
+    let popup_w = content_w.max(50).min(f.area().width.saturating_sub(4));
+    let popup_h = (message.lines().count() as u16 + 7).min(f.area().height.saturating_sub(4));
+    let area = centered_rect_size(popup_w, popup_h, f.area());
+    f.render_widget(Clear, area);
+    let block = Block::default().borders(Borders::ALL).border_type(BorderType::Plain).border_style(Style::default().fg(Color::Cyan));
+    f.render_widget(block, area);
+    let inner = inner(area, 2, 1);
+    f.render_widget(Paragraph::new(Span::styled(title, Style::default().fg(Color::Cyan).add_modifier(Modifier::BOLD))).alignment(Alignment::Center), Rect { height: 1, ..inner });
+    let msg_h = message.lines().count() as u16;
+    f.render_widget(Paragraph::new(message.to_string()).style(Style::default().fg(Color::Gray)).alignment(Alignment::Left), Rect { x: inner.x + 2, y: inner.y + 2, width: inner.width.saturating_sub(4), height: msg_h });
+    let ok = Span::styled("[ OK ]", Style::default().fg(Color::Black).bg(Color::Cyan).add_modifier(Modifier::BOLD));
+    f.render_widget(Paragraph::new(ok).alignment(Alignment::Center), Rect { y: inner.y + inner.height.saturating_sub(2), height: 1, ..inner });
+}
+
+pub fn draw_ok_dialog_styled(f: &mut Frame, _app: &AppState, title: &str, lines: &[Line]) {
+    let content_w = lines.iter().map(|l| l.width() as u16).max().unwrap_or(20).max(title.len() as u16) + 10;
+    let popup_w = content_w.max(50).min(f.area().width.saturating_sub(4));
+    let popup_h = (lines.len() as u16 + 7).min(f.area().height.saturating_sub(4));
+    let area = centered_rect_size(popup_w, popup_h, f.area());
+    f.render_widget(Clear, area);
+    let block = Block::default().borders(Borders::ALL).border_type(BorderType::Plain).border_style(Style::default().fg(Color::Cyan));
+    f.render_widget(block, area);
+    let inner = inner(area, 2, 1);
+    f.render_widget(Paragraph::new(Span::styled(title, Style::default().fg(Color::Cyan).add_modifier(Modifier::BOLD))).alignment(Alignment::Center), Rect { height: 1, ..inner });
+    f.render_widget(Paragraph::new(lines.to_vec()).style(Style::default()).alignment(Alignment::Left), Rect { x: inner.x + 2, y: inner.y + 2, width: inner.width.saturating_sub(4), height: lines.len() as u16 });
+    let ok = Span::styled("[ OK ]", Style::default().fg(Color::Black).bg(Color::Cyan).add_modifier(Modifier::BOLD));
+    f.render_widget(Paragraph::new(ok).alignment(Alignment::Center), Rect { y: inner.y + inner.height.saturating_sub(2), height: 1, ..inner });
+}
+
+fn centered_rect_size(w: u16, h: u16, r: Rect) -> Rect {
+    let popup = Layout::default().direction(Direction::Vertical)
+        .constraints([Constraint::Length((r.height.saturating_sub(h))/2), Constraint::Length(h), Constraint::Length((r.height.saturating_sub(h))/2)])
+        .split(r);
+    Layout::default().direction(Direction::Horizontal)
+        .constraints([Constraint::Length((r.width.saturating_sub(w))/2), Constraint::Length(w), Constraint::Length((r.width.saturating_sub(w))/2)])
+        .split(popup[1])[1]
+}
+
+/// Draw a sub-menu (e.g. Config management).
+pub fn draw_sub_menu(
+    f: &mut Frame,
+    app: &AppState,
+    title: &str,
+    items: &[&str],
+    descs: &[&str],
+    state: &mut ListState,
+) {
+    let chunks = standard_layout(f.area(), items.len());
+
+    draw_header(f, chunks[0], app);
+
+    let title_p = Paragraph::new(Span::styled(
+        title,
+        Style::default()
+            .fg(Color::Yellow)
+            .add_modifier(Modifier::BOLD),
+    ));
+    f.render_widget(title_p, chunks[1]);
+
+    draw_select_list(f, chunks[2], items, descs, "↑/↓ navigate  Enter select  Esc back", state);
+    draw_status_bar(f, chunks[3], app);
+}
+
+/// Draw a simple text screen with a "press any key" prompt.
+pub fn draw_text_screen(
+    f: &mut Frame,
+    app: &AppState,
+    lines: &[Line],
+    prompt: &str,
+) {
+    let chunks = standard_layout(f.area(), lines.len());
+    draw_header(f, chunks[0], app);
+
+    f.render_widget(Paragraph::new(lines.to_vec()), chunks[2]);
+
+    let prompt_p = Paragraph::new(Span::styled(
+        prompt,
+        Style::default().fg(Color::DarkGray),
+    ))
+    .alignment(Alignment::Center);
+    f.render_widget(prompt_p, chunks[3]);
+}
+
+/// Draw a file/folder picker list.
+pub fn draw_picker(
+    f: &mut Frame,
+    app: &AppState,
+    items: &[&str],
+    descs: &[&str],
+    state: &mut ListState,
+) {
+    draw_picker_with_info(f, app, items, descs, state, None);
+}
+
+/// Draw a file/folder picker list with an extra selected-item info line
+/// (e.g. showing the full filename of the highlighted .bak file).
+pub fn draw_picker_with_info(
+    f: &mut Frame,
+    app: &AppState,
+    items: &[&str],
+    descs: &[&str],
+    state: &mut ListState,
+    selected_info: Option<&str>,
+) {
+    let chunks = standard_layout(f.area(), items.len());
+    draw_header(f, chunks[0], app);
+
+    let prompt = "↑/↓ navigate  Enter select  Esc cancel";
+    draw_select_list_with_info(f, chunks[2], items, descs, prompt, state, selected_info);
+    draw_status_bar(f, chunks[3], app);
+}
+
+// ── internal drawing helpers ───────────────────────────────────────────────
+
+fn standard_layout(area: Rect, menu_items: usize) -> Vec<Rect> {
+    let menu_height = menu_items as u16 + 4; // items + gaps + prompt line
+    Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([
+            Constraint::Length(3),                          // header
+            Constraint::Length(2),                          // dashboard
+            Constraint::Min(menu_height.min(area.height.saturating_sub(6))), // menu
+            Constraint::Length(1),                          // status bar
+        ])
+        .split(area).to_vec()
+}
+
+fn draw_header(f: &mut Frame, area: Rect, app: &AppState) {
+    let header_block = Block::default()
+        .borders(Borders::BOTTOM)
+        .border_type(BorderType::Plain)
+        .border_style(Style::default().fg(Color::Cyan));
+
+    let chunks = Layout::default()
+        .direction(Direction::Horizontal)
+        .constraints([
+            Constraint::Length(20),
+            Constraint::Min(0),
+        ])
+        .split(inner(area, 1, 0));
+
+    let title_line = Line::from(vec![
+        Span::styled("NOTALTERRA", Style::default().fg(Color::Cyan).add_modifier(Modifier::BOLD)),
+        Span::raw(" "),
+        Span::styled(app.version.clone(), Style::default().fg(Color::DarkGray)),
+    ]);
+    f.render_widget(Paragraph::new(title_line), chunks[0]);
+
+    let path_line = if let Some(ref path) = app.save_path {
+        let max_w = chunks[1].width.saturating_sub(2) as usize;
+        let display = truncate_path_tail(path, max_w);
+        Paragraph::new(Span::styled(display, Style::default().fg(Color::Gray)))
+            .alignment(Alignment::Right)
+    } else {
+        Paragraph::new(Span::styled(
+            "no save folder selected",
+            Style::default().fg(Color::DarkGray),
+        ))
+        .alignment(Alignment::Right)
+    };
+    f.render_widget(path_line, chunks[1]);
+    f.render_widget(header_block, area);
+}
+
+fn draw_status_dashboard(f: &mut Frame, area: Rect, app: &AppState) {
+    let live = Span::styled(
+        format!(" Save: {} ", if app.save_path.is_some() { app.live_save_count.to_string() } else { "—".into() }),
+        Style::default().fg(Color::Green),
+    );
+    let bak = Span::styled(
+        format!(" Backups: {} ", app.backup_count),
+        Style::default().fg(Color::Yellow),
+    );
+    let ini = Span::styled(
+        format!(" .ini backup: {} ", if app.has_ini_backup { "yes" } else { "no" }),
+        Style::default().fg(if app.has_ini_backup { Color::Green } else { Color::DarkGray }),
+    );
+
+    let line = Line::from(vec![
+        Span::raw("  "),
+        live,
+        Span::raw("  "),
+        bak,
+        Span::raw("  "),
+        ini,
+    ]);
+
+    f.render_widget(Paragraph::new(line), area);
+}
+
+fn draw_select_list(
+    f: &mut Frame,
+    area: Rect,
+    items: &[&str],
+    descs: &[&str],
+    prompt: &str,
+    state: &mut ListState,
+) {
+    let list_area = Rect {
+        height: area.height.saturating_sub(1),
+        ..area
+    };
+
+    let list_items: Vec<ListItem> = items
+        .iter()
+        .map(|item| {
+            ListItem::new(Span::raw(*item))
+                .style(Style::default())
+        })
+        .collect();
+
+    let list = List::new(list_items)
+        .highlight_style(
+            Style::default()
+                .bg(Color::Cyan)
+                .fg(Color::Black)
+                .add_modifier(Modifier::BOLD),
+        )
+        .highlight_symbol(" ")
+        .repeat_highlight_symbol(true);
+
+    f.render_stateful_widget(list, list_area, state);
+
+    // Description line for the highlighted item
+    let desc_idx = state.selected().unwrap_or(0).min(descs.len().saturating_sub(1));
+    let desc = descs.get(desc_idx).copied().unwrap_or("");
+    let desc_line = Paragraph::new(Span::styled(
+        format!("  {desc}"),
+        Style::default().fg(Color::DarkGray),
+    ));
+
+    f.render_widget(
+        desc_line,
+        Rect {
+            x: area.x,
+            y: area.y + area.height.saturating_sub(1),
+            width: area.width,
+            height: 1,
+        },
+    );
+
+    // Prompt at bottom-right
+    let prompt_len = prompt.len() as u16;
+    if area.width > prompt_len + 2 {
+        let prompt_p = Paragraph::new(Span::styled(
+            prompt,
+            Style::default().fg(Color::DarkGray),
+        ))
+        .alignment(Alignment::Right);
+        f.render_widget(
+            prompt_p,
+            Rect {
+                x: area.x,
+                y: area.y + area.height.saturating_sub(1),
+                width: area.width.saturating_sub(2),
+                height: 1,
+            },
+        );
+    }
+}
+
+fn draw_select_list_with_info(
+    f: &mut Frame,
+    area: Rect,
+    items: &[&str],
+    descs: &[&str],
+    prompt: &str,
+    state: &mut ListState,
+    selected_info: Option<&str>,
+) {
+    let extra = if selected_info.is_some() { 1u16 } else { 0u16 };
+    let list_area = Rect {
+        height: area.height.saturating_sub(1 + extra),
+        ..area
+    };
+
+    let list_items: Vec<ListItem> = items
+        .iter()
+        .map(|item| {
+            ListItem::new(Span::raw(*item))
+                .style(Style::default())
+        })
+        .collect();
+
+    let list = List::new(list_items)
+        .highlight_style(
+            Style::default()
+                .bg(Color::Cyan)
+                .fg(Color::Black)
+                .add_modifier(Modifier::BOLD),
+        )
+        .highlight_symbol(" ")
+        .repeat_highlight_symbol(true);
+
+    f.render_stateful_widget(list, list_area, state);
+
+    // Description line for the highlighted item
+    let base_y = area.y + area.height.saturating_sub(1 + extra);
+    let desc_idx = state.selected().unwrap_or(0).min(descs.len().saturating_sub(1));
+    let desc = descs.get(desc_idx).copied().unwrap_or("");
+    let desc_line = Paragraph::new(Span::styled(
+        format!("  {desc}"),
+        Style::default().fg(Color::DarkGray),
+    ));
+
+    f.render_widget(
+        desc_line,
+        Rect {
+            x: area.x,
+            y: base_y,
+            width: area.width,
+            height: 1,
+        },
+    );
+
+    // Selected-item info line (e.g. filename)
+    if let Some(info) = selected_info {
+        let info_line = Paragraph::new(Span::styled(
+            format!("  → {info}"),
+            Style::default().fg(Color::White),
+        ));
+        f.render_widget(
+            info_line,
+            Rect {
+                x: area.x,
+                y: base_y + 1,
+                width: area.width,
+                height: 1,
+            },
+        );
+    }
+
+    // Prompt at bottom-right
+    let prompt_len = prompt.len() as u16;
+    if area.width > prompt_len + 2 {
+        let prompt_p = Paragraph::new(Span::styled(
+            prompt,
+            Style::default().fg(Color::DarkGray),
+        ))
+        .alignment(Alignment::Right);
+        f.render_widget(
+            prompt_p,
+            Rect {
+                x: area.x,
+                y: area.y + area.height.saturating_sub(1),
+                width: area.width.saturating_sub(2),
+                height: 1,
+            },
+        );
+    }
+}
+
+fn draw_status_bar(f: &mut Frame, area: Rect, app: &AppState) {
+    if let Some(ref msg) = app.status_message {
+        let color = match app.status_style {
+            StatusStyle::Success => Color::Green,
+            StatusStyle::Warning => Color::Yellow,
+            StatusStyle::Error => Color::Red,
+            StatusStyle::Info => Color::Cyan,
+            StatusStyle::Neutral => Color::Gray,
+        };
+
+        let icon = match app.status_style {
+            StatusStyle::Success => "√",
+            StatusStyle::Warning => "!",
+            StatusStyle::Error => "×",
+            StatusStyle::Info => "i",
+            StatusStyle::Neutral => " ",
+        };
+
+        let line = Line::from(vec![
+            Span::styled(
+                format!(" [{icon}] {msg}"),
+                Style::default().fg(color),
+            ),
+        ]);
+        f.render_widget(Paragraph::new(line), area);
+    }
+
+    // Spinner
+    if app.spinner_active {
+        if let Some(start) = app.spinner_start {
+            let elapsed = start.elapsed().as_millis() as u64;
+            let frames = &["⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"];
+            let idx = ((elapsed / 80) % frames.len() as u64) as usize;
+            let spinner = Paragraph::new(Span::styled(
+                frames[idx],
+                Style::default().fg(Color::Cyan),
+            ));
+            f.render_widget(
+                spinner,
+                Rect {
+                    x: area.width.saturating_sub(4),
+                    y: area.y,
+                    width: 3,
+                    height: 1,
+                },
+            );
+        }
+    }
+}
+
+/// Truncate a path to show the tail (most specific directories).
+/// e.g. `C:\Users\...\Subnautica2\Saved\SaveGames` → `…\Subnautica2\Saved\SaveGames`
+fn truncate_path_tail(path: &str, max_width: usize) -> String {
+    if path.len() <= max_width {
+        return path.to_string();
+    }
+    let keep = max_width.saturating_sub(3);
+    if keep == 0 {
+        return "…".to_string();
+    }
+    let tail = &path[path.len().saturating_sub(keep)..];
+    // Walk forward to a path separator so we don't split mid-component
+    if let Some(sep_pos) = tail.find(&['\\', '/'][..]) {
+        let start = path.len().saturating_sub(keep) + sep_pos;
+        format!("…{}", &path[start..])
+    } else {
+        format!("…{}", tail)
+    }
+}
+
+/// Create a centered rectangle for modal overlays.
+fn centered_rect(percent_x: u16, percent_y: u16, r: Rect) -> Rect {
+    let popup_layout = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([
+            Constraint::Percentage((100 - percent_y) / 2),
+            Constraint::Percentage(percent_y),
+            Constraint::Percentage((100 - percent_y) / 2),
+        ])
+        .split(r);
+
+    Layout::default()
+        .direction(Direction::Horizontal)
+        .constraints([
+            Constraint::Percentage((100 - percent_x) / 2),
+            Constraint::Percentage(percent_x),
+            Constraint::Percentage((100 - percent_x) / 2),
+        ])
+        .split(popup_layout[1])[1]
+}
+
+/// Shrink a rect by a margin on all sides.
+fn inner(rect: Rect, margin_x: u16, margin_y: u16) -> Rect {
+    Rect {
+        x: rect.x + margin_x,
+        y: rect.y + margin_y,
+        width: rect.width.saturating_sub(margin_x * 2),
+        height: rect.height.saturating_sub(margin_y * 2),
+    }
+}