Each test file covers 10 real API tests matching the C SDK reference:
health_check, validate_keys, get_languages, execute, execute_error,
session_list, session_lifecycle, service_list, snapshot_list, image_list.
All tests skip cleanly without credentials. No soft passes.
Updated all 7 Makefiles to run dedicated functional test files.
Python: auto-creates .venv with pytest, requests, aiohttp.
JavaScript: auto npm install when node_modules missing, uses npm test for ESM.
Go: auto-detects go binary from PATH/~/.local/go/usr/local/go, copies tests
into src/ for same-package constraint, adds go.mod for sync SDK.
