feat: Implement complete fleet management system GUI application

[javad204513]

This commit delivers the full implementation of the fleet management system as per the detailed plan.

Modules Included:

• User Authentication (Admin, Operator roles)
• Vehicle Management (CRUD)
• Driver Management (CRUD)
• Shift Planning (Templates and Assignments CRUD)
• Mission Management (Request, Evaluate, Assign, Start, Complete, Cancel lifecycle)
• Advanced Reporting (Driver Performance, Vehicle Utilization) with Excel/PDF export (basic PDF styling, Jalali font dependent)
• Management Dashboard (KPIs and Mission Status Pie Chart with Matplotlib)

Key Features:

• Modular design with UI components for each management area.
• Database interaction via SQLAlchemy ORM with SQLite.
• Dynamic UI updates based on selections and data changes.
• Basic input validation and user feedback messages.

Further Considerations Post-Delivery:

• Comprehensive unit and integration testing.
• Robust Jalali font integration for PDF reports and charts (ensure Vazir.ttf or similar is correctly pathed/distributed).
• Advanced database features (e.g., complex indexing, automated backups if not handled externally).
• UI/UX refinements based on user feedback.
• Detailed user and developer documentation.