fix(testing): harden CI DB initialization and ASGI lifespan setup for stable API tests

[weijt606]

Summary

This PR stabilizes backend CI tests by fixing database/table initialization timing and ASGI test app startup behavior across the latest three commits.

Scope

• Commit 1: 2efd67c
• Commit 2: 63d64ce
• Commit 3: f3bd135

Problem

CI intermittently failed on API tests with:

• UndefinedTableError: relation "resources" does not exist
• async runtime instability around test setup/startup ordering

The failures happened when tests queried DB-backed routes before schema creation or before app startup lifecycle was properly applied.

What Changed

• Added session-level test stabilization for async DB usage and loop consistency.
• Added explicit CI schema bootstrap (Base.metadata.create_all) before test execution in backend and integration jobs.
• Updated ASGI test client fixture to run FastAPI lifespan context explicitly, ensuring startup/shutdown hooks run during tests.

Why This Fix Works

• The resources table is now guaranteed to exist before API tests run.
• Test environment startup order is deterministic.
• API routes depending on startup-initialized resources no longer race CI timing.

Validation

• Local CI-like backend run (not integration) passes:
  • 15 passed, 1 skipped, 1 deselected
• Integration compare test path remains passing in CI-like env.
• The previously reported UndefinedTableError path is covered by explicit schema bootstrap plus lifespan-managed test client setup.

Risk

• Low risk.
• Changes are isolated to test/CI setup and do not alter production runtime behavior.

Expected Outcome

• Backend CI tests should no longer fail due to missing resources table or startup ordering issues.