feat(health): BA-113 validate health endpoint query parameters and reject unsupported probe options

[ranjeetprabhatedu-dotcom]

Summary

This PR implements BA-113 to validate query parameters on the health check endpoint, rejecting unsupported probe options while cleanly handling accepted defaults and diagnostic options.

• Validates incoming probe query options against SUPPORTED_PROBES (liveness, readiness, startup, full), throwing BadRequestException on unrecognized values.
• Retains default behavior falling back to full probe when parameter is omitted.
• Adds verbose query parameter support returning system uptime and Node version for telemetry inspection.
• Fixes exception import in coverage.ts to use HttpException with HttpStatus.TOO_MANY_REQUESTS.
• Adds unit tests in app.controller.spec.ts covering default probe behavior, supported probe acceptance, unsupported probe rejection with detailed error messaging, and verbose flag output.
• Scoped strictly to the 3 allowlisted files:
  • BackendAcademy/src/health/health.controller.ts
  • BackendAcademy/src/health/coverage.ts
  • BackendAcademy/src/app.controller.spec.ts

Closes #1026