Major updates: LinkedIn auto-posting, timezone fixes, and Docker improvements

Features:
- Add LinkedIn OAuth integration and auto-posting functionality
- Add scheduler service for automated post publishing
- Add metadata field to generated_posts for LinkedIn URLs
- Add privacy policy page for LinkedIn API compliance
- Add company management features and employee accounts
- Add license key system for company registrations

Fixes:
- Fix timezone issues (use UTC consistently across app)
- Fix datetime serialization errors in database operations
- Fix scheduling timezone conversion (local time to UTC)
- Fix import errors (get_database -> db)

Infrastructure:
- Update Docker setup to use port 8001 (avoid conflicts)
- Add SSL support with nginx-proxy and Let's Encrypt
- Add LinkedIn setup documentation
- Add migration scripts for schema updates

Services:
- Add linkedin_service.py for LinkedIn API integration
- Add scheduler_service.py for background job processing
- Add storage_service.py for Supabase Storage
- Add email_service.py improvements
- Add encryption utilities for token storage

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

Dockerfile

@@ -28,12 +28,12 @@ RUN useradd --create-home --shell /bin/bash appuser && \
     chown -R appuser:appuser /app
 USER appuser
 
-# Expose port
-EXPOSE 8000
+# Expose port (default 8001, can be overridden by PORT env var)
+EXPOSE 8001
 
-# Health check
+# Health check (uses PORT env var with 8001 fallback)
 HEALTHCHECK --interval=30s --timeout=10s --start-period=5s --retries=3 \
-    CMD python -c "import httpx; httpx.get('http://localhost:8000/login', timeout=5)" || exit 1
+    CMD python -c "import os, httpx; port = os.getenv('PORT', '8001'); httpx.get(f'http://localhost:{port}/login', timeout=5)" || exit 1
 
-# Run the application
-CMD ["python", "-m", "uvicorn", "src.web.app:app", "--host", "0.0.0.0", "--port", "8000"]
+# Run the application (uses PORT env var with 8001 fallback)
+CMD sh -c "python -m uvicorn src.web.app:app --host 0.0.0.0 --port ${PORT:-8001}"