Bug: has_any_success allowed one healthy source to give overall 'ready'
when another source was stale/not_started/running — masking failures.
Fix:
- Added has_any_stale and has_any_running tracking
- Overall status is 'degraded' if ANY source is failed/stale/running
- Overall status is 'ready' ONLY when ALL enabled sources are healthy
- 'not_started' when no sources are enabled
- readiness (ready flag) still NOT blocked by import health (A01 requirement)
Verification:
- 7/7 readiness tests pass
- 124/124 Python tests pass (1 skipped)
- Stale source now shows 'degraded' instead of 'ready'
- Failed source still shows 'degraded'
- All healthy sources show 'ready'
ik
883e63aa8b