feat: Phase 4 — inspection sessions (create, execute, complete)

Backend:
- InspectionSession + InspectionRecord models with alembic migration
- 6 API endpoints: create, list, get detail, save records, complete, delete
- Auto pass/fail judgment for numeric (spec range) and boolean items
- Completed inspections are immutable, required items enforced on complete
- 14 new tests (total 53/53 passed)

Frontend:
- Inspection list page with in_progress/completed tabs
- Template select modal for starting new inspections
- Inspection execution page with data-type-specific inputs
- Auto-save with 1.5s debounce, manual save button
- Completion modal with notes and required item validation
- Read-only view for completed inspections
- Pass/fail badges and color-coded item cards

Co-Authored-By: Claude Opus 4 <noreply@anthropic.com>

main.py

@@ -22,6 +22,7 @@ from src.tenant.manager import TenantNotFoundError, InvalidTenantIdError
 from src.api.machines import router as machines_router
 from src.api.equipment_parts import router as equipment_parts_router
 from src.api.templates import router as templates_router
+from src.api.inspections import router as inspections_router
 
 logger = logging.getLogger(__name__)
 
@@ -53,6 +54,7 @@ app.include_router(auth_admin_router)
 app.include_router(machines_router)
 app.include_router(equipment_parts_router)
 app.include_router(templates_router)
+app.include_router(inspections_router)
 
 
 @app.get("/api/health")