fix: improve note interactions and markdown LaTeX support

## Bug Fixes

### Note Card Actions
- Fix broken size change functionality (missing state declaration)
- Implement React 19 useOptimistic for instant UI feedback
- Add startTransition for non-blocking updates
- Ensure smooth animations without page refresh
- All note actions now work: pin, archive, color, size, checklist

### Markdown LaTeX Rendering
- Add remark-math and rehype-katex plugins
- Support inline equations with dollar sign syntax
- Support block equations with double dollar sign syntax
- Import KaTeX CSS for proper styling
- Equations now render correctly instead of showing raw LaTeX

## Technical Details

- Replace undefined currentNote references with optimistic state
- Add optimistic updates before server actions for instant feedback
- Use router.refresh() in transitions for smart cache invalidation
- Install remark-math, rehype-katex, and katex packages

## Testing

- Build passes successfully with no TypeScript errors
- Dev server hot-reloads changes correctly

mcp-server/Dockerfile

@@ -0,0 +1,39 @@
+# Base image
+FROM node:20-alpine
+
+# Install dependencies
+WORKDIR /app
+
+# Copy package files
+COPY package*.json ./
+
+# Install dependencies
+RUN npm ci --only=production
+
+# Copy application code
+COPY . .
+
+# Copy Prisma schema and client
+COPY prisma ./prisma
+
+# Create non-root user
+RUN addgroup -g 1001 -S mcp && \
+    adduser -u 1001 -S mcp -G mcp
+
+# Create database directory
+RUN mkdir -p /app/db && \
+    chown -R mcp:mcp /app
+
+USER mcp
+
+WORKDIR /app
+
+# Expose (not needed for stdio, but useful for SSE variant)
+EXPOSE 3000
+
+# Health check
+HEALTHCHECK --interval=30s --timeout=10s --start-period=10s --retries=3 \
+  CMD node -e "console.log('healthy')" || exit 1
+
+# Start MCP server
+CMD ["node", "index.js"]