feat: add task filtering, search, priority, and statistics

[Rashed-alothman]

Summary

This PR adds advanced querying capabilities to the TMS API, including task filtering, sorting, and a priority system.

Changes Made

New Features

• Added priority field to Task model (low, medium, high, urgent)
• Implemented filtering by completion status
• Implemented filtering by priority level
• Implemented sorting by creation date, due date, and priority
• Added validation for priority values
• Added case-insensitive priority handling

API Enhancements

• GET /homepage/api/tasks now accepts query parameters:
  • ?completed=true/false - filter by completion status
  • ?priority=low/medium/high/urgent - filter by priority
  • ?sort=created_at/due_date/priority - sort results
• POST /homepage/api/tasks/add_Tasks now accepts priority field
• All endpoints now have comprehensive error handling with SQLAlchemy rollback

Technical Improvements

• Added error message constants for consistency
• Enhanced logging for debugging
• Improved error handling across all routes
• Added database transaction rollback on errors

Testing

• All 19 tests passing
• New tests added for filtering and sorting
• Priority validation tests included
• Error handling tests comprehensive

Database Changes

• Added priority column to tasks table (default: 'low')
• Updated Task model with priority field

Breaking Changes

None - all changes are backwards compatible

Documentation

• Updated code comments
• Added route documentation in file header