USER REQUEST:
'in the fixture details page of the web interface after the list of matches a file upload button with progress bar to upload a zip file that will be associated with all the matches that doesn't have already one'

IMPLEMENTATION COMPLETED:

1. Backend Route (app/upload/routes.py):
   - Added /upload/fixture/<fixture_id>/zip endpoint for fixture-level ZIP uploads
   - Filters matches by fixture_id and excludes those with existing ZIP files
   - Processes single ZIP upload and associates with all qualifying matches
   - Comprehensive error handling and database transaction management
   - Integration with existing file upload handler for large file support

2. Frontend Template (app/templates/main/fixture_detail.html):
   - Added fixture upload component after match list as requested
   - Progress bar with real-time upload tracking
   - Status messages and visual feedback for user experience
   - Conditional display - only shows when matches without ZIP files exist
   - Informational content explaining the bulk upload functionality

3. JavaScript Functionality:
   - AJAX upload with XMLHttpRequest for progress tracking
   - Real-time progress bar updates during file upload
   - Comprehensive error handling and recovery
   - Automatic file selection event handling
   - Status management with success/error states

4. Template Logic:
   - Filters matches to show only those without ZIP files
   - Groups matches by fixture_id for bulk operations
   - Conditional rendering based on upload eligibility
   - Integration with existing match display structure

TECHNICAL FEATURES:
- ✅ Bulk upload: One ZIP file associated with multiple matches
- ✅ Progress tracking: Real-time upload progress bar
- ✅ File filtering: Only affects matches without existing ZIP files
- ✅ Large file support: Up to 2GB with streaming capabilities
- ✅ Error handling: Network and upload error recovery
- ✅ User feedback: Clear status messages and visual indicators
- ✅ Database integrity: Transaction-based updates with rollback
- ✅ Memory optimization: Chunked upload processing

TESTING VERIFICATION:
- Route registration confirmed: POST /upload/fixture/<fixture_id>/zip
- Template components verified: upload form, progress bar, status tracking
- JavaScript functions confirmed: startFixtureUpload, updateFixtureProgress
- File handler integration tested: large file support ready
- Template logic verified: conditional display and match filtering

The fixture-level ZIP upload feature is fully implemented and ready for use.