feat(windows): persist size + position across restarts via tauri-plugin-window-state

Without this, every secondary window (preview overlay, task float,
transcript viewer) opened at whatever spot Tauri / the compositor picked,
which was especially noticeable on Wayland where placement hints are
advisory. Main window's position was also lost on restart.

Registering tauri_plugin_window_state in the builder gives automatic
per-window-label save + restore. State lives in app-data/window-state.json;
fresh installs still fall back to the builder defaults (no changes to
inner_size on any of the four windows). Covers OpenWhispr issue #605 and
the broader UX pain.

No frontend changes — the plugin is purely backend. Regenerated ACL
manifests / desktop + linux schemas pick up the plugin registration.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src-tauri/Cargo.toml

@@ -29,6 +29,7 @@ tauri-plugin-opener = "2"
 tauri-plugin-dialog = "2"
 tauri-plugin-global-shortcut = "2"
 tauri-plugin-updater = "2"
+tauri-plugin-window-state = "2"
 
 # Serialisation
 serde = { version = "1", features = ["derive"] }

src-tauri/gen/schemas/desktop-schema.json

@@ -2545,6 +2545,48 @@
           "type": "string",
           "const": "updater:deny-install",
           "markdownDescription": "Denies the install command without any pre-configured scope."
+        },
+        {
+          "description": "This permission set configures what kind of\noperations are available from the window state plugin.\n\n#### Granted Permissions\n\nAll operations are enabled by default.\n\n\n#### This default permission set includes:\n\n- `allow-filename`\n- `allow-restore-state`\n- `allow-save-window-state`",
+          "type": "string",
+          "const": "window-state:default",
+          "markdownDescription": "This permission set configures what kind of\noperations are available from the window state plugin.\n\n#### Granted Permissions\n\nAll operations are enabled by default.\n\n\n#### This default permission set includes:\n\n- `allow-filename`\n- `allow-restore-state`\n- `allow-save-window-state`"
+        },
+        {
+          "description": "Enables the filename command without any pre-configured scope.",
+          "type": "string",
+          "const": "window-state:allow-filename",
+          "markdownDescription": "Enables the filename command without any pre-configured scope."
+        },
+        {
+          "description": "Enables the restore_state command without any pre-configured scope.",
+          "type": "string",
+          "const": "window-state:allow-restore-state",
+          "markdownDescription": "Enables the restore_state command without any pre-configured scope."
+        },
+        {
+          "description": "Enables the save_window_state command without any pre-configured scope.",
+          "type": "string",
+          "const": "window-state:allow-save-window-state",
+          "markdownDescription": "Enables the save_window_state command without any pre-configured scope."
+        },
+        {
+          "description": "Denies the filename command without any pre-configured scope.",
+          "type": "string",
+          "const": "window-state:deny-filename",
+          "markdownDescription": "Denies the filename command without any pre-configured scope."
+        },
+        {
+          "description": "Denies the restore_state command without any pre-configured scope.",
+          "type": "string",
+          "const": "window-state:deny-restore-state",
+          "markdownDescription": "Denies the restore_state command without any pre-configured scope."
+        },
+        {
+          "description": "Denies the save_window_state command without any pre-configured scope.",
+          "type": "string",
+          "const": "window-state:deny-save-window-state",
+          "markdownDescription": "Denies the save_window_state command without any pre-configured scope."
         }
       ]
     },

src-tauri/gen/schemas/linux-schema.json

@@ -2545,6 +2545,48 @@
           "type": "string",
           "const": "updater:deny-install",
           "markdownDescription": "Denies the install command without any pre-configured scope."
+        },
+        {
+          "description": "This permission set configures what kind of\noperations are available from the window state plugin.\n\n#### Granted Permissions\n\nAll operations are enabled by default.\n\n\n#### This default permission set includes:\n\n- `allow-filename`\n- `allow-restore-state`\n- `allow-save-window-state`",
+          "type": "string",
+          "const": "window-state:default",
+          "markdownDescription": "This permission set configures what kind of\noperations are available from the window state plugin.\n\n#### Granted Permissions\n\nAll operations are enabled by default.\n\n\n#### This default permission set includes:\n\n- `allow-filename`\n- `allow-restore-state`\n- `allow-save-window-state`"
+        },
+        {
+          "description": "Enables the filename command without any pre-configured scope.",
+          "type": "string",
+          "const": "window-state:allow-filename",
+          "markdownDescription": "Enables the filename command without any pre-configured scope."
+        },
+        {
+          "description": "Enables the restore_state command without any pre-configured scope.",
+          "type": "string",
+          "const": "window-state:allow-restore-state",
+          "markdownDescription": "Enables the restore_state command without any pre-configured scope."
+        },
+        {
+          "description": "Enables the save_window_state command without any pre-configured scope.",
+          "type": "string",
+          "const": "window-state:allow-save-window-state",
+          "markdownDescription": "Enables the save_window_state command without any pre-configured scope."
+        },
+        {
+          "description": "Denies the filename command without any pre-configured scope.",
+          "type": "string",
+          "const": "window-state:deny-filename",
+          "markdownDescription": "Denies the filename command without any pre-configured scope."
+        },
+        {
+          "description": "Denies the restore_state command without any pre-configured scope.",
+          "type": "string",
+          "const": "window-state:deny-restore-state",
+          "markdownDescription": "Denies the restore_state command without any pre-configured scope."
+        },
+        {
+          "description": "Denies the save_window_state command without any pre-configured scope.",
+          "type": "string",
+          "const": "window-state:deny-save-window-state",
+          "markdownDescription": "Denies the save_window_state command without any pre-configured scope."
         }
       ]
     },

src-tauri/src/lib.rs

@@ -128,6 +128,12 @@ pub fn run() {
         .plugin(tauri_plugin_dialog::init())
         .plugin(tauri_plugin_global_shortcut::Builder::new().build())
         .plugin(tauri_plugin_updater::Builder::new().build())
+        // Remember size + position of every window across app restarts.
+        // Without this, secondary windows (preview overlay, task float,
+        // transcript viewer) open at whatever spot the compositor picks,
+        // which feels random. State is persisted per-window-label to
+        // app-data/window-state.json.
+        .plugin(tauri_plugin_window_state::Builder::default().build())
         .setup(|app| {
             // Initialise database (blocking in setup — runs once at startup)
             let db_path = database_path();