ci: add service host discovery and strict policy docs validation

- Add multi-candidate host discovery (localhost, host.docker.internal, gateway) in api-endpoint-tests
- Pass discovered service host via AITBC_API_HOST environment variable to test script
- Update test_api_endpoints.py to use AITBC_API_HOST for all service URLs
- Add validate-policies-strict job to docs-validation workflow for policy Markdown files
- Add job names to package-tests matrix for better CI output clarity
- Add --import

.gitea/workflows/python-tests.yml

@@ -78,7 +78,8 @@ jobs:
             apps/wallet/tests/ \
             packages/py/aitbc-crypto/tests/ \
             packages/py/aitbc-sdk/tests/ \
-            --tb=short -q --timeout=30 \
+            --tb=short -q --timeout=30 --import-mode=importlib \
+            --ignore=tests/production \
             --ignore=apps/coordinator-api/tests/test_confidential*.py
 
           echo "✅ Python tests completed"