[TEST] Add contract tests for frontend API client against backend OpenAPI schema

[utksh1]

Problem

SecuScan needs a production-grade improvement in this area: Frontend/backend contract safety..

Scope

Generate or validate TypeScript API types from backend schema and fail tests when response contracts drift.

Acceptance Criteria

• The implementation is focused and does not introduce unrelated UI, docs, lockfile, or formatting churn.
• Security-sensitive behavior has explicit negative tests where applicable.
• Existing tests continue to pass, and new tests cover the main success and failure paths.
• Documentation or configuration examples are updated when operator behavior changes.

Verification

Tests should catch a deliberate backend response shape mismatch or stale frontend type.

Difficulty

Hard, useful issue intended for experienced contributors.

[VIDYANKSHINI]

I would like to work on this issue.

I am interested in contributing to the frontend/backend contract validation improvements for SecuScan by adding contract tests that verify API response consistency against the backend OpenAPI schema. I can work on implementing automated validation or generated TypeScript API types to ensure frontend contracts remain synchronized with backend responses and fail appropriately when schema drift occurs.

Planned scope:

• Add contract tests for frontend API client validation
• Generate or validate TypeScript types from the backend OpenAPI schema
• Detect and fail tests on backend response shape mismatches
• Add coverage for stale or incompatible frontend response types
• Include focused negative/error-path testing where applicable
• Ensure existing tests continue to pass alongside the new coverage
• Keep the implementation scoped without unrelated UI, formatting, or lockfile changes

Please assign this issue to me if it is still available.