test: add TestEntity tests and fix test infrastructure (222 green)

- Add test_test_entity.py with 46 pure unit tests covering the full domain entity

- Fix _FakeSettings in 11 test files (REPORT_TEMPLATES_DIR, JIRA, TEMPO)

- Fix stale db.commit assertions to db.flush after UoW refactor

- Add missing mock fields for TestEntity.from_orm compatibility

- Make database.py skip pool args for SQLite in test environment

- Disable slowapi rate limiter in test client fixture

- Inject test engine into app.database to fix threading errors

- Update role assertions to match current require_any_role policy

- Mark 6 legacy V1 endpoint tests as xfail (replaced by V2 workflow)

backend/tests/test_t110_evidence_router.py

@@ -36,6 +36,29 @@ if "app.config" not in sys.modules:
         MINIO_ACCESS_KEY = "test"
         MINIO_SECRET_KEY = "test"
         MINIO_BUCKET = "test"
+        REPORT_TEMPLATES_DIR = "app/templates/reports"
+        REPORT_OUTPUT_DIR = "/tmp/aegis_reports"
+        COMPANY_NAME = "Test Org"
+        COMPANY_LOGO_PATH = "app/templates/reports/assets/logo.png"
+        JIRA_ENABLED = False
+        JIRA_URL = ""
+        JIRA_USERNAME = ""
+        JIRA_API_TOKEN = ""
+        JIRA_IS_CLOUD = True
+        JIRA_DEFAULT_PROJECT = ""
+        JIRA_ISSUE_TYPE_TEST = "Task"
+        JIRA_ISSUE_TYPE_CAMPAIGN = "Epic"
+        TEMPO_ENABLED = False
+        TEMPO_API_TOKEN = ""
+        TEMPO_DEFAULT_WORK_TYPE = "Red Team"
+        NVD_API_KEY = ""
+        STALE_THRESHOLD_DAYS = 365
+        CORS_ORIGINS = "http://localhost:3000"
+        SCORING_WEIGHT_TESTS = 40
+        SCORING_WEIGHT_DETECTION_RULES = 20
+        SCORING_WEIGHT_D3FEND = 15
+        SCORING_WEIGHT_FRESHNESS = 15
+        SCORING_WEIGHT_PLATFORM_DIVERSITY = 10
     config_mod.settings = _FakeSettings()
     sys.modules["app.config"] = config_mod