[Desktop] Window state is reset to default on every launch #15165

Description

Describe the bug

The .window-state.json file is always reset to default values when OpenCode Desktop launches. Custom window size and position settings are not persisted.

Steps to reproduce

1. Launch OpenCode Desktop
2. Resize and reposition the window
3. Close OpenCode Desktop completely
4. Check ~/.config/ai.opencode.desktop.dev/.window-state.json - custom values are saved
5. Launch OpenCode Desktop again
6. Window opens with default size (800x600, maximized: true)
7. Check .window-state.json - values are reset to defaults:

{
  "main": {
    "width": 800,
    "height": 600,
    "x": 80,
    "y": 0,
    "prev_x": 80,
    "prev_y": 0,
    "maximized": true,
    "visible": true,
    "decorated": true,
    "fullscreen": false
  }
}

Display: 4K (3840x2160) with 125% scaling
Config path: ~/.config/ai.opencode.desktop.dev/.window-state.json

Expected behavior

Window size and position should persist across sessions. The .window-state.json values should be read and applied on launch.

Actual behavior

Window state is reset to hardcoded defaults on every launch, ignoring .window-state.json.

Additional context

This may be related to Tauri's window-state plugin not correctly reading the saved state file, or the state being overwritten before the window is created.

Plugins

No response

OpenCode version

1.2.14

Steps to reproduce

1. Close OpenCode Desktop completely (ensure no process is running)
2. Launch OpenCode Desktop
3. Resize the window to a custom size (e.g., drag to make it 1400x900)
4. Move the window to a different position
5. Unmaximize the window if it was maximized
6. Close OpenCode Desktop
7. Open ~/.config/ai.opencode.desktop.dev/.window-state.json and verify custom values are saved:

   {
     "main": {
       "width": 1400,
       "height": 900,
       "x": 836,
       "y": 414,
       "maximized": false,
       ...
     }
   }

8. Launch OpenCode Desktop again
9. Observe: Window opens maximized at default size (800x600)
10. Check ~/.config/ai.opencode.desktop.dev/.window-state.json again
11. Observe: File content is reset to defaults:

{
 "main": {
   "width": 800,
   "height": 600,
   "x": 80,
   "y": 0,
   "prev_x": 80,
   "prev_y": 0,
   "maximized": true,
   "visible": true,
   "decorated": true,
   "fullscreen": false
 }
}

Screenshot and/or share link

No response

Operating System

openSUSE Leap 15.6 / 16, SUSE Linux Enterprise 15 SP6, SP7

Terminal

No response