Add complete project management system with role-based access control:
**Core Features:**
- Project creation and management for Admins/Supervisors
- Time tracking with optional project selection and notes
- Project-based filtering and reporting in history
- Enhanced export functionality with project data
- Team-specific project assignments
**Database Changes:**
- New Project model with full relationships
- Enhanced TimeEntry model with project_id and notes
- Updated migration scripts with rollback support
- Sample project creation for testing
**User Interface:**
- Project management templates (create, edit, list)
- Enhanced time tracking with project dropdown
- Project filtering in history page
- Updated navigation for role-based access
- Modern styling with hover effects and responsive design
**API Enhancements:**
- Project validation and access control
- Updated arrive endpoint with project support
- Enhanced export functions with project data
- Role-based route protection
**Migration Support:**
- Comprehensive migration scripts (migrate_projects.py)
- Updated main migration script (migrate_db.py)
- Detailed migration documentation
- Rollback functionality for safe deployment
**Role-Based Access:**
- Admins: Full project CRUD operations
- Supervisors: Project creation and management
- Team Leaders: View team hours with projects
- Team Members: Select projects when tracking time
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
