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/utils.py

@@ -390,6 +390,12 @@ def build_tui_stats_text(tracer: Any, agent_config: dict[str, Any] | None = None
         stats_text.append(" · ", style="white")
         stats_text.append(f"${total_stats['cost']:.2f}", style="white")
 
+    caido_url = getattr(tracer, "caido_url", None)
+    if caido_url:
+        stats_text.append("\n")
+        stats_text.append("Caido: ", style="bold white")
+        stats_text.append(caido_url, style="white")
+
     return stats_text