feat(ui): themed startup splash with deferred window show (#1030)

* feat(ui): add themed startup splash with deferred window show

Show a theme-aware loading splash before the Vite bundle mounts, hide the
native window until it paints, and use per-theme logo gradient colors.

* docs: note startup splash in CHANGELOG and credits for PR #1030

* docs: attribute PR #1030 startup splash to cucadmuh

src/config/settingsCredits.ts

@@ -154,6 +154,7 @@ const CONTRIBUTOR_ENTRIES = [
       'Audio: Symphonia 0.6 migration with libopus adapter 0.3; ranged-stream start latency fix (probe seek-gate) and a probe timeout so a stalled stream no longer hangs playback start (PR #999)',
       'Offline experience — unified media layout (cache/library/favorites), localPlaybackStore, library-index Offline Library, favorites auto-sync, cached album/playlist/artist pin reconcile, mixed-server offline queue, and single mediaDir setting (PR #1008)',
       'Offline browse — local-bytes catalog when server is down, integration contract (context/policy/resolvers), disconnect nav fork, Home stale-cache feed, read-only context menus, PlayerBar rating/favorite guard (PR #1017)',
+      'Themed startup splash before Vite loads — deferred window show, per-theme logo gradient (PR #1030)',
     ],
   },
   {

src/config/startupSplashPalettes.ts

@@ -0,0 +1,71 @@
+/** Splash colors aligned with bundled theme semantic tokens (`--bg-app`, etc.). */
+export type StartupSplashPalette = {
+  bg: string;
+  text: string;
+  muted: string;
+  accent: string;
+  track: string;
+  /** Sidebar logo gradient start (`--logo-color-start` / `--accent`). */
+  logoStart: string;
+  /** Sidebar logo gradient end (`--logo-color-end` / `--accent-2`). */
+  logoEnd: string;
+};
+
+export const BUILTIN_SPLASH_PALETTES: Record<string, StartupSplashPalette> = {
+  mocha: {
+    bg: '#1e1e2e',
+    text: '#cdd6f4',
+    muted: '#a6adc8',
+    accent: '#cba6f7',
+    track: '#313244',
+    logoStart: '#cba6f7',
+    logoEnd: '#89b4fa',
+  },
+  latte: {
+    bg: '#eff1f5',
+    text: '#4c4f69',
+    muted: '#6c6f85',
+    accent: '#8839ef',
+    track: '#ccd0da',
+    logoStart: '#8839ef',
+    logoEnd: '#1e66f5',
+  },
+  'kanagawa-wave': {
+    bg: '#1F1F28',
+    text: '#DCD7BA',
+    muted: '#727169',
+    accent: '#7E9CD8',
+    track: '#2A2A37',
+    logoStart: '#7E9CD8',
+    logoEnd: '#957FB8',
+  },
+  'stark-hud': {
+    bg: '#0b0f15',
+    text: '#e0f7fa',
+    muted: '#7da5aa',
+    accent: '#00f2ff',
+    track: '#141b24',
+    logoStart: '#00f2ff',
+    logoEnd: '#7df9ff',
+  },
+  'vision-dark': {
+    bg: '#0d0b12',
+    text: '#f2eef8',
+    muted: '#a6a2b8',
+    accent: '#ffd700',
+    track: '#16131e',
+    logoStart: '#ffd700',
+    logoEnd: '#a07af8',
+  },
+  'vision-navy': {
+    bg: '#0a1628',
+    text: '#e8eef8',
+    muted: '#9caac2',
+    accent: '#ffd700',
+    track: '#12213a',
+    logoStart: '#ffd700',
+    logoEnd: '#a07af8',
+  },
+};
+
+export const BUILTIN_THEME_IDS = Object.keys(BUILTIN_SPLASH_PALETTES);