[IMPROVEMENT] Improve health check to verify Taskwarrior availability.

[gaurav02081]

Description

This PR improves the health check endpoint by verifying that the Taskwarrior (task) binary is available on the system.

Previously, the health endpoint always returned 200 OK, even if Taskwarrior was missing. The updated behavior returns 503 Service Unavailable with a clear status message when the required binary is not found, ensuring the service only reports itself as healthy when it can actually function

Checklist

• Ran npx prettier --write . (for formatting)
• Ran gofmt -w . (for Go backend)
• Ran npm test (for JS/TS testing)
• Added unit tests, if applicable
• Verified all tests pass
• Updated documentation, if needed

Additional Notes

I have verified the changes locally by simulating a missing Taskwarrior dependency inside the running container !

Baseline (normal state):

curl -s -i http://localhost:8000/health

Returns:

HTTP/1.1 200 OK
{"service":"ccsync-backend","status":"healthy"}

---

Simulated failure (Taskwarrior removed):

docker-compose exec -u root backend mv /usr/local/bin/task /usr/local/bin/task.bak
curl -s -i http://localhost:8000/health

Returns:

HTTP/1.1 503 Service Unavailable
{"service":"ccsync-backend","status":"unhealthy: taskwarrior binary not found"}

---

Restored dependency:

docker-compose exec -u root backend mv /usr/local/bin/task.bak /usr/local/bin/task
curl -s -i http://localhost:8000/health

Returns:

HTTP/1.1 200 OK
{"service":"ccsync-backend","status":"healthy"}

---> This change helps catch misconfigured or broken environments.

[github-actions]

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