test : add unit tests for health_check and root endpoint functions

[tmdeveloper007]

Summary of What Needs to be Done:
Add unit tests for the health_check and root endpoint functions in backend/secuscan/main.py. These are FastAPI route handlers that can be tested in isolation by constructing a minimal FastAPI app or by testing them as async functions with mocked dependencies.

Changes that Need to be Made:
Create testing/backend/unit/test_main_endpoints.py (standalone unit tests) covering:

1. health_check():

   • Returns a JSONResponse with status field
   • Returns 200 status code
   • Response body contains expected fields (e.g., status, version)

2. root():

   • Returns an HTMLResponse
   • Response has 200 status code
   • Response body contains expected HTML content

Use FastAPI TestClient or construct minimal app state for testing. Mock any app-level dependencies that are not relevant to these endpoints. Run with --noconftest to avoid the full app initialization.

Import from backend.secuscan.main directly. Do NOT import the full app (which requires all routes to be loaded).

Impact that it would Provide:

• Reliability: Ensures health check and root endpoints return expected responses
• Testing: Adds coverage for main.py which currently has no unit tests
• Maintainability: Documents the expected API surface for these endpoints

Note: This task is being handled by tmdeveloper007 — please assign to that account when picking it up.