feat(plugin): add font-customizer plugin

[kev2block]

This PR adds a new plugin: Font Customizer.

Features

• Two modes:
  • Simple: set one global font for the entire app.
  • Advanced: set per-scope fonts: Title, Artist, Lyrics.
• Uses Google Fonts on demand (no manual CSS needed).
• Applies instantly via CSS variables; no reload required.
• Clean defaults (all “System Default”).

Screenshots

Playlist view

Lyrics view

Implementation

• src/plugins/font-customizer/index.ts — plugin registration, defaults.
• src/plugins/font-customizer/menu.ts — menu UI (mode + popular font radio lists).
• src/plugins/font-customizer/renderer.ts — loads Google Fonts, sets CSS vars, applies to player/lyrics surfaces.
• src/plugins/font-customizer/types.ts — FontCustomizerConfig, FontMode, popularFonts.

Tested

• Windows 11, Node v22.18.0, pnpm v10.15.0
• Dev (pnpm dev) and packaged builds.

Note: You could add custom fonts via plain CSS (@font-face) in a user stylesheet,
but this plugin is simpler: it fetches Google Fonts automatically and scopes them
reliably without manual CSS maintenance.

No changes to existing plugins or core behavior.

[ArjixWasTaken]

Not quite, look at other plugins for how they apply stylesheets.