feat: Add UX optimizations - skeletons and optimistic hooks

- Add Skeletons.tsx with TastingListSkeleton, ChartSkeleton, etc.
- Add useOptimistic.ts hooks for React 19 optimistic updates
- Update stats page to use skeleton loading instead of spinner
- Remove force-dynamic exports (12 files) for SSG compatibility
- Note: PPR (cacheComponents) tested but reverted - requires RSC-first refactor

next.config.mjs

@@ -8,6 +8,8 @@ const nextConfig = {
     // React Compiler for automatic memoization (React 19+)
     reactCompiler: true,
     experimental: {
+        // Note: cacheComponents (PPR) disabled - requires Suspense boundaries for all auth contexts
+        // Can be enabled later after refactoring to RSC-first architecture
         serverActions: {
             bodySizeLimit: '10mb',
         },