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/schemas/evidence.py

@@ -5,6 +5,8 @@ from datetime import datetime
 
 from pydantic import BaseModel, ConfigDict
 
+from app.models.enums import TeamSide
+
 
 class EvidenceOut(BaseModel):
     """Representation of an evidence record returned by the API.
@@ -18,6 +20,15 @@ class EvidenceOut(BaseModel):
     sha256_hash: str
     uploaded_by: uuid.UUID | None = None
     uploaded_at: datetime | None = None
+    team: TeamSide = TeamSide.red
+    notes: str | None = None
     download_url: str | None = None
 
     model_config = ConfigDict(from_attributes=True)
+
+
+class EvidenceUpload(BaseModel):
+    """Metadata sent alongside an evidence file upload."""
+
+    team: TeamSide
+    notes: str | None = None