Manager test coverage: unit service + component tests for all domains #9684
Description
Improve Backend.AI Manager test coverage across all service domains.
439 Action classes exist but many lack unit service tests. 9 domains have no component tests at all. 112 of 300 Client SDK API methods (37%) are not exercised in component/integration tests.
Scope:
- Add unit service tests (mocked repository) for all untested actions across 27 domains
- Create component tests for 9 domains that currently have none
- Cover untested Client SDK methods in component tests
- All new test files only — no modification to existing large test files or shared conftest.py
10 parallel tasks, 20 SP total.
JIRA Issue: BA-4892