fix: sonarqube findings, deprecations, ownership enforcement, test fi…

[Maneesh-Relanto]

…eld names

SonarQube / code quality fixes:

• src/rbac/storage/sqlalchemy_adapter.py: extract _FK_ROLES_ID constant for duplicate 'rbac_roles.id' literal; rename _Session -> _session_factory to resolve naming clash with _session() method
• src/rbac/core/models/init.py: replace datetime.utcnow with _utcnow() helper returning timezone-aware datetime.now(timezone.utc)
• test-apps/02-flask-blog-api/app.py: refactor into Flask Blueprints to reduce cognitive complexity (67 -> minimal); fix utcnow; add perm_comment_delete to reader role
• test-apps/02-flask-blog-api/decorators.py: extract _fetch_owned_resource, _build_permission_context, forbidden_response helpers; add ownership enforcement via OWNERSHIP_OVERRIDE_ROLES; add MSG* constants
• test-apps/02-flask-blog-api/models.py: fix utcnow deprecation
• test-apps/02-flask-blog-api/storage.py: fix utcnow deprecation (5 places)
• test-apps/02-flask-blog-api/test_api.py: fix test_update_others_post_as_author to target correct post (/posts/4 not /posts/1)
• test-apps/03-fastapi-blog-api/dependencies.py: extract _resolve_resource, _build_context, _raise_forbidden; add OWNERSHIP_OVERRIDE_ROLES enforcement
• test-apps/03-fastapi-blog-api/seed_data.py: extract title constants; add NOSONAR on demo passwords; remove unnecessary f-string
• test-apps/03-fastapi-blog-api/test_api.py: remove unused variable; add NOSONAR on hardcoded test credentials

Pre-existing test model field-name mismatches fixed:

• tests/conftest.py: username -> name, metadata -> attributes, fix Permission fields (resource -> resource_type, drop domain)
• tests/test_models.py: same field-name fixes + assertion updates
• tests/test_storage.py: username -> name
• tests/integration/test_complete_workflows.py: username -> name, metadata -> attributes, Permission resource=obj -> resource_type=obj.type
• tests/property/test_authorization_invariants.py: username -> name, Permission resource=obj -> resource_type=obj.type

Test results after fixes:

• test-apps/02-flask-blog-api: 34/34 passing
• test-apps/03-fastapi-blog-api: 39/39 passing
• tests/test_sqlalchemy_storage.py: 50/50 passing