feat: Phase 3 - CRUD core for Techniques, Tests and Evidence (T-014 to T-017)

- Add Pydantic schemas for Technique, Test and Evidence
- Add CRUD endpoints for Techniques (list with filters, detail, create, update, review)
- Add CRUD endpoints for Tests (create, detail, update, validate, reject)
- Add evidence upload with SHA-256 integrity and presigned download URLs
- Add MinIO/S3 storage client with bucket auto-creation on startup
- Add status_service to recalculate technique coverage from test results
- Add require_any_role RBAC dependency for multi-role authorization
- Update README with API endpoints reference and project structure

backend/app/services/status_service.py

@@ -0,0 +1,36 @@
+"""Service for recalculating the global status of a Technique
+based on the state and result of its associated tests."""
+
+from sqlalchemy.orm import Session
+
+from app.models.enums import TechniqueStatus
+from app.models.technique import Technique
+
+
+def recalculate_technique_status(db: Session, technique: Technique) -> None:
+    """Recompute ``technique.status_global`` from its tests and commit.
+
+    Rules
+    -----
+    - No tests → ``not_evaluated``
+    - Any test not yet ``validated`` → ``in_progress``
+    - All validated and all ``detected`` → ``validated``
+    - All validated and any ``partially_detected`` → ``partial``
+    - Otherwise → ``not_covered``
+    """
+    tests = technique.tests
+
+    if not tests:
+        technique.status_global = TechniqueStatus.not_evaluated
+    elif any(t.state != "validated" for t in tests):
+        technique.status_global = TechniqueStatus.in_progress
+    else:
+        results = [t.result for t in tests]
+        if all(r == "detected" for r in results):
+            technique.status_global = TechniqueStatus.validated
+        elif any(r == "partially_detected" for r in results):
+            technique.status_global = TechniqueStatus.partial
+        else:
+            technique.status_global = TechniqueStatus.not_covered
+
+    db.commit()