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/vitest.config.ts

@@ -0,0 +1,37 @@
+import { defineConfig } from 'vitest/config'
+import path from 'path'
+
+export default defineConfig({
+  test: {
+    globals: true,
+    environment: 'node',
+    setupFiles: ['./tests/setup.ts'],
+    include: ['tests/unit/**/*.test.ts', 'tests/migration/**/*.test.ts'],
+    exclude: ['node_modules', 'tests/e2e'],
+    coverage: {
+      provider: 'v8',
+      reporter: ['text', 'json', 'html'],
+      exclude: [
+        'node_modules/',
+        'tests/',
+        '**/*.test.ts',
+        '**/*.spec.ts',
+        'prisma/',
+        'next-env.d.ts'
+      ],
+      thresholds: {
+        lines: 80,
+        functions: 80,
+        branches: 80,
+        statements: 80
+      }
+    },
+    testTimeout: 30000,
+    hookTimeout: 30000
+  },
+  resolve: {
+    alias: {
+      '@': path.resolve(__dirname, '.'),
+    },
+  },
+})