feat: Expose Caido proxy port to host for human-in-the-loop interaction

Users can now access the Caido web UI from their browser to inspect traffic,
replay requests, and perform manual testing alongside the automated scan.

- Map Caido port (48080) to a random host port in DockerRuntime
- Add caido_port to SandboxInfo and track across container lifecycle
- Display Caido URL in TUI sidebar stats panel with selectable text
- Bind Caido to 0.0.0.0 in entrypoint (requires image rebuild)
- Bump sandbox image to 0.1.12
- Restore discord link in exit screen

strix/interface/main.py

@@ -462,7 +462,7 @@ def display_completion_message(args: argparse.Namespace, results_path: Path) ->
     console.print("\n")
     console.print(panel)
     console.print()
-    console.print("[#60a5fa]models.strix.ai[/]")
+    console.print("[#60a5fa]models.strix.ai[/]  [dim]·[/]  [#60a5fa]discord.gg/strix-ai[/]")
     console.print()