Add mobile app support and opening training feature

This commit implements iOS/Android mobile app support using Capacitor
and adds a comprehensive opening training feature with LLM-powered
explanations.

## Mobile App Infrastructure

- Add Capacitor configuration for iOS/Android builds
- Create mobile build script that excludes API routes
- Update Next.js config for conditional static export
- Add layout components with generateStaticParams for static builds
- Generate 500+ static pages for offline mobile use

## Chess Engine Abstraction

- Create ChessEngine interface for pluggable implementations
- Add LocalEngine (GPL - uses stockfish.js in browser)
- Add RemoteEngine (proprietary - calls API server)
- Factory pattern selects engine based on environment
- Enables GPL compliance for web, proprietary for mobile

## Opening Training Feature

- Interactive opening repertoire training
- Move validation with engine-backed feedback
- LLM explanations using Gemini API
- Wikipedia integration for opening context
- Opening family grouping (e4, d4, c4, etc.)
- Session state management
- Real-time move feedback with evaluation

Components:
- OpeningSelector: Browse and select openings by family
- OpeningTrainer: Main training interface with chessboard
- MoveFeedback: Display move quality and LLM explanations
- WikipediaSummary: Show opening history and context
- ErrorBoundary: Graceful error handling

Services:
- openingLoader: Load and filter opening database
- engineService: Engine evaluation wrapper
- moveValidator: Validate moves against repertoire
- feedbackGenerator: Generate contextual feedback
- wikipediaService: Fetch and cache Wikipedia data
- sessionManager: Track training session state

## Wikipedia Integration

- Automatic Wikipedia article fetching for openings
- Client-side and server-side caching
- Sanitized summaries with proper formatting
- Link opening database to Wikipedia slugs
- API endpoints for on-demand fetching

## Docker Improvements

- Add entrypoint script for automatic data setup
- Fetch Wikipedia data on first container startup
- Generate opening move index automatically
- Remove generated data from git (public/openings/*.json, public/wikipedia/*.json)
- Add READMEs explaining data requirements
- Update .gitignore for generated files

## Dual Licensing Strategy

- Add LICENSING.md explaining dual licensing approach
- GPL-3.0 for web builds (includes Stockfish)
- Proprietary option for mobile builds (no GPL code)
- Single codebase, multiple licensing models
- Legal compliance documented

## API Endpoints

- POST /api/v1/llm/opening-explanation - Get LLM move explanations
- GET /api/v1/wikipedia/summary - Fetch Wikipedia summaries

## Type Updates

- Add openingTraining types
- Update Tutor component to use ChessEngine interface
- Add Gemini error handling types

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Dockerfile

@@ -49,6 +49,15 @@ COPY --from=builder /app/public ./public
 COPY --from=builder /app/.next/standalone ./
 COPY --from=builder /app/.next/static ./.next/static
 
+# Copy scripts and node_modules needed for Wikipedia/opening setup
+COPY --from=builder /app/scripts ./scripts
+COPY --from=builder /app/node_modules ./node_modules
+COPY --from=builder /app/package.json ./package.json
+
+# Copy entrypoint script and make executable
+COPY scripts/docker-entrypoint.sh /usr/local/bin/
+RUN chmod +x /usr/local/bin/docker-entrypoint.sh
+
 # Set ownership to non-root user
 RUN chown -R nextjs:nodejs /app
 
@@ -66,5 +75,8 @@ ENV HOSTNAME="0.0.0.0"
 HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
   CMD node -e "require('http').get('http://localhost:3050/api/health', (r) => {process.exit(r.statusCode === 200 ? 0 : 1)})" || exit 1
 
+# Use entrypoint for initialization
+ENTRYPOINT ["/usr/local/bin/docker-entrypoint.sh"]
+
 # Start the application
 CMD ["node", "server.js"]