💡 Add app-wide UI zoom/scaling with keyboard shortcuts

[mouadlotfi]

Description

Add the ability to scale the entire Fladder UI (text, buttons, images, spacing, etc.) similar to browser zoom functionality. This would make the app more accessible and usable across different screen sizes and user preferences.

Requested Feature

Implement app-wide UI scaling with keyboard shortcuts:

• Ctrl+Plus (or Cmd+Plus on macOS) - Zoom in / increase UI scale
• Ctrl+Minus (or Cmd+Minus on macOS) - Zoom out / decrease UI scale
• Ctrl+0 (or Cmd+0 on macOS) - Reset to default scale

Add a setting in Settings → Visual to set a default zoom level that persists between sessions.

Use Cases

• Accessibility - Users with vision impairments who need larger UI elements
• High-DPI displays - Users on 4K/5K monitors where the UI appears too small
• Large TV screens - Android TV users where UI elements are too small (see issue 🐛 Text and some elements on player UI are too small on a large television screen #650, 🐛 Bring down title icon and clock in player UI on Android TV to a more reasonable size #733)
• Personal preference - Users who simply prefer larger or smaller UI
• Multi-monitor setups - Different zoom levels for different screen sizes

Suggested Implementation

Use Flutter's MediaQuery.textScaler and scale factor to adjust the entire UI:

// In ClientSettingsModel
@Default(1.0) double uiScale  // Range: 0.5 to 2.0

// In main app widget
MediaQuery(
  data: MediaQuery.of(context).copyWith(
    textScaler: TextScaler.linear(settings.uiScale),
  ),
  child: ...
)

Add keyboard shortcuts in the existing shortcut system:

enum GlobalHotKeys {
  search,
  exit,
  toggleSideBar,
  zoomIn,      // New
  zoomOut,     // New
  zoomReset,   // New
}

Benefits

• Improves accessibility for users with vision impairments
• Makes the app usable on a wider range of screen sizes
• Addresses existing issues with UI being too small on TV (🐛 Text and some elements on player UI are too small on a large television screen #650, 🐛 Bring down title icon and clock in player UI on Android TV to a more reasonable size #733)
• Standard feature in most desktop applications
• Easy to implement using Flutter's built-in scaling
• Zoom level persists between app sessions

Platform

All platforms (Windows, Linux, macOS, Android, iOS, Android TV)

Additional Context

• Similar to browser zoom (Ctrl+Plus/Ctrl+Minus)
• Should scale everything: text, buttons, images, spacing, icons
• Setting should persist between app sessions
• Could also add mouse wheel zoom (Ctrl+Scroll) as an enhancement

Related Issues

• 🐛 Text and some elements on player UI are too small on a large television screen #650 - Text and some elements on player UI are too small on a large television screen
• 🐛 Bring down title icon and clock in player UI on Android TV to a more reasonable size #733 - Bring down title icon and clock in player UI on Android TV to a more reasonable size

[schembriaiden]

Duplicate of this: #519

If you would like keybinds keep the discussion to just the other one.

[PartyDonut]

Closed as duplicate of #519. Make sure to upvote and add to existing discussions, this increase the chance of it being picked up.