Sprint 2: Ticket Engine + SLA + Photo Uploads

- Ticket CRUD with full 15-status lifecycle enforcement
- Auto-generated ticket numbers (PAV-YYYY-NNNNN)
- Status transitions validated and auto-logged to timeline
- Reopen with 7-day window + auto-escalation to Ama
- SLA engine: priority-based deadlines and breach detection
- Photo uploads to uploads/ with multipart support
- Category system seeded from PRD §7 taxonomy (20 top-level)
- Flat and tree category listing endpoints
- SLA status check endpoint (/api/tickets/{id}/sla)
- Paginated ticket listing with filters

.gitignore

@@ -4,6 +4,8 @@ __pycache__/
 *.sqlite3
 .env
 .venv/
+uploads/
+test_*.py
 venv/
 *.egg-info/
 dist/