Add: config for controlling debug overlay visibility of tauri

docs/CONFIG_REFERENCE.md

@@ -39,6 +39,7 @@ recovery_hotkey = "Ctrl+Alt+P"
 
 [frontend]
 backend = "bevy"
+debug_overlay_visible = false
 ```
 
 ## Notes
@@ -48,3 +49,4 @@ backend = "bevy"
 - `window.click_through` is deprecated and ignored at runtime; it is always forced to `false`.
 - On Windows, `recovery_hotkey` now forces `visible = true` and `always_on_top = true` for recovery.
 - `frontend.backend` selects runtime frontend implementation (`bevy` or `tauri`).
+- `frontend.debug_overlay_visible` controls whether tauri window debug diagnostics panel is shown.