feat(phase-11): implement Red/Blue business logic services (T-106, T-107, T-108)

T-106: Create test_workflow_service.py with state-machine transitions for the complete test lifecycle (draft -> red_executing -> blue_evaluating -> in_review -> validated/rejected), dual validation by Red/Blue leads, and reopen capability with field cleanup.

T-107: Update status_service.py to use detection_result from Blue Team instead of legacy result field, and differentiate between partial progress (some validated) vs all-in-progress states.

T-108: Create atomic_import_service.py that downloads the Atomic Red Team repo as a ZIP (avoiding API rate limits), parses all atomics YAML files, and creates idempotent TestTemplate records mapped to MITRE techniques.

Includes validation tests for all three tasks (19 checks total).

backend/app/routers/evidence.py

@@ -128,5 +128,7 @@ def _evidence_to_out(evidence: Evidence) -> EvidenceOut:
         sha256_hash=evidence.sha256_hash,
         uploaded_by=evidence.uploaded_by,
         uploaded_at=evidence.uploaded_at,
+        team=evidence.team,
+        notes=evidence.notes,
         download_url=get_presigned_url(evidence.file_path),
     )