feat(review-queue): trigger review_required on new test templates

Extends the review queue triggers to cover test template imports:
- atomic_import_service: flags techniques when new Atomic Red Team
  templates are imported
- caldera_import_service: same for Caldera templates
- lolbas_import_service: same for LOLBAS templates
- test_templates router (manual creation): flags the technique when
  an admin/lead creates a custom template via the API

Pattern is identical to the Sigma/Elastic detection rule approach:
collect new mitre_ids during the loop, bulk-update after commit.
Manual creation does a single technique lookup and sets the flag
inside the existing UnitOfWork.

backend/app/routers/test_templates.py

@@ -31,6 +31,7 @@ from sqlalchemy.orm import Session
 from app.database import get_db
 from app.dependencies.auth import get_current_user, require_any_role
 from app.domain.unit_of_work import UnitOfWork
+from app.models.technique import Technique
 from app.models.user import User
 from app.schemas.test_template import (
     TestTemplateCreate,
@@ -178,6 +179,15 @@ def create_template(
     """Create a custom test template."""
     template = create_template_svc(db, **payload.model_dump())
     with UnitOfWork(db) as uow:
+        # Flag the associated technique for review — new template available
+        if template.mitre_technique_id:
+            technique = (
+                db.query(Technique)
+                .filter(Technique.mitre_id == template.mitre_technique_id)
+                .first()
+            )
+            if technique:
+                technique.review_required = True
         log_action(
             db,
             user_id=current_user.id,