# Functional Spec: Persistence

## 1. Scope
The application needs to persist user preferences and session state across restarts.
The primary use case is remembering the **Last Opened Project**.

## 2. Storage Mechanism
*   **Library:** `tauri-plugin-store`
*   **File:** `store.json` (located in the App Data directory).
*   **Keys:**
    *   `last_project_path`: String (Absolute path).
    *   (Future) `theme`: String.
    *   (Future) `recent_projects`: Array<String>.

## 3. Startup Logic
1.  **Backend Init:**
    *   Load `store.json`.
    *   Read `last_project_path`.
    *   Verify path exists and is a directory.
    *   If valid:
        *   Update `SessionState`.
        *   Return "Project Loaded" status to Frontend on init.
    *   If invalid/missing:
        *   Clear key.
        *   Remain in `Idle` state.

## 4. Frontend Logic
*   **On Mount:**
    *   Call `get_current_project()` command.
    *   If returns path -> Show Workspace.
    *   If returns null -> Show Selection Screen.
*   **On "Open Project":**
    *   After successful open, save path to store.
*   **On "Close Project":**
    *   Clear `SessionState`.
    *   Remove `last_project_path` from store.
    *   Show Selection Screen.