fix: unify theme system - fix theme switching persistence

- Unified localStorage key to 'theme-preference' across all components
- Fixed header.tsx using wrong localStorage key ('theme' instead of 'theme-preference')
- Added localStorage hybrid persistence for instant theme changes
- Removed router.refresh() which was causing stale data revert
- Replaced Blue theme with Sepia
- Consolidated auth() calls to prevent race conditions
- Updated UserSettingsData types to include all themes

keep-notes/prisma/client-generated/package.json

@@ -1,5 +1,5 @@
 {
-  "name": "prisma-client-3d6220144f5583920cbea4466cc4b7cd1590576c45f6d92c95c9ec7f0e8cd94d",
+  "name": "prisma-client-aac99853c38843b923b5ef02e79fc02f024613e74dbfa218769f719178707434",
   "main": "index.js",
   "types": "index.d.ts",
   "browser": "index-browser.js",