Add heartbeat endpoint and tests

[seapagan]

This pull request adds a new health check endpoint to the service, allowing external systems or users to verify that the service is running. It also includes a corresponding integration test to ensure the endpoint works as expected.

Health check endpoint:

• Added a new /heartbeat route in heartbeat.py that returns a simple JSON response indicating the service is up.
• Registered the new heartbeat router in the main API router configuration in routes.py.

Testing:

• Added an integration test in test_home_routes.py to verify that the /heartbeat endpoint returns the expected response.

[codacy-production]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
✅ +0.00% (target: -1.00%)	✅ 100.00%

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (9c23bea)	1909	1909	100.00%
Head commit (a11e4f7)	1915 (+6)	1915 (+6)	100.00% (+0.00%)

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#795)	7	7	100.00%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

See your quality gate settings    Change summary preferences