Implement MVP: Anonymous feedback submission (User Story 1)

Complete implementation of Phase 1-3 (64 tasks):
- Phase 1: Project setup with Flask, pytest, configuration
- Phase 2: Core infrastructure (auth, models, services, testing)
- Phase 3: Anonymous feedback submission with file uploads

Features:
- Anonymous feedback submission (text and/or up to 3 file attachments)
- Multi-language support (any language accepted)
- File validation (type, size) and virus scanning (ClamAV)
- Product management with active/archived status
- File-based storage with YAML metadata
- User authentication system (Flask-Login)
- CSRF protection and rate limiting
- Test coverage: 10 passing tests (contract + integration)

Security:
- No IP address logging (FR-055 compliance)
- File type whitelist and size limits (10MB max)
- Virus scanning with graceful degradation
- Filename sanitization and secure storage

Test Results:
- 8 contract tests passed
- 2 integration tests passed
- End-to-end workflow verified

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

requirements.txt

@@ -0,0 +1,12 @@
+Flask==3.0.0
+Flask-Login==0.6.3
+Flask-Limiter==3.5.0
+Flask-WTF==1.2.1
+anthropic==0.8.0
+clamd==1.0.2
+bcrypt==4.1.2
+PyYAML==6.0.1
+pytest==7.4.3
+pytest-flask==1.3.0
+python-dotenv==1.0.0
+Werkzeug==3.0.1