fix(health): separate liveness probe from readiness checks

[NP-compete]

Summary

• Add liveness_response() that returns a lightweight "process alive" check (uptime, version, shutdown state) with no dependency probing
• Route /livez through liveness_response() so Kubernetes only restarts the pod when the process is genuinely stuck or shutting down
• All other probe paths (/health, /healthz, /readyz) continue running full dependency checks

Closes #224

Test plan

• test_livez_skips_dependency_checks -- verifies /livez does not call get_health_status()
• test_readyz_runs_dependency_checks -- verifies /readyz still runs full checks and returns 503 on failure
• test_alive_when_not_shutting_down -- verifies liveness returns 200 with "alive" status
• test_503_when_shutting_down -- verifies liveness returns 503 during graceful shutdown
• All 22 existing health tests continue to pass

[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between c47e57f and a12b6c6.

📒 Files selected for processing (2)

• deep_agent/aegra/health.py
• tests/unit/aegra/test_health.py

🔗 Linked repositories identified

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• redhat-data-and-ai/template-mcp (manual)
• redhat-data-and-ai/template-ui (manual)

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Walkthrough

The health module adds liveness_response and the /livez route. Liveness checks return 200 while active and 503 during shutdown without dependency checks. Other health paths retain shutdown handling and full dependency evaluation. Unit tests cover liveness, shutdown, dependency-check invocation, and readiness failures.

Fixed issue severity: <fixed_issue_severity>Medium</fixed_issue_severity>

Suggested reviewers: anish701

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 62.50% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	The changes implement issue #224 by isolating /livez from dependency checks while preserving full checks for readiness and other health paths.
Out of Scope Changes check	✅ Passed	The changes and tests stay within the linked issue scope of separating liveness and readiness health behavior.
Description check	✅ Passed	The description accurately explains the liveness and readiness changes and includes relevant tests.
Title check	✅ Passed	The title clearly and concisely describes separating liveness probes from readiness checks.

✨ Finishing Touches 💡 1

🛠️ Fix failing CI checks 💡

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests

🚀 Post-Merge Actions

• Update changelog

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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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