Description

Adds end-to-end assignee support to the Task API, fixes task completion so it preserves the existing priority and stays idempotent, and expands automated coverage around validators, startup behavior, and edge cases. This PR also refreshes BUG_REPORT.md and adds SUBMISSION.md to match the current state of the repository.

Type of Change

• feat: New feature
• fix: Bug fix
• refactor: Code refactoring
• docs: Documentation update
• test: Adding or updating tests
• chore: Build/dependency updates
• perf: Performance improvement
• hotfix: Urgent production fix

Related Issues

None. This is a take-home assignment submission branch, and the remaining open defects are documented in BUG_REPORT.md.

Changes Made

• Added PATCH /tasks/:id/assign with assignee validation and reassignment support.
• Extended task storage to include assignee on task records.
• Fixed task completion so it preserves priority and does not overwrite completedAt on repeat calls.
• Added and expanded Jest and Supertest coverage for validation branches, null-body handling, app startup, and stats edge cases.
• Updated BUG_REPORT.md to reflect the current open bugs.
• Added SUBMISSION.md and removed the long-form audit notes file.

Testing

• Unit tests added/updated
• Integration tests added/updated
• E2E tests added/updated
• Manual testing performed
• Tested on dev environment

Verification used:

• npm test
• npm run coverage

Screenshots

Checklist

• My code follows the project's coding standards
• I have performed a self-review of my code
• I have commented my code where necessary
• I have updated the documentation (if needed)
• My changes generate no new warnings
• I have added tests that prove my fix/feature works
• New and existing tests pass locally
• Any dependent changes have been merged

Additional Notes

Some tests are intentionally red because they document the remaining open bugs listed in [BUG_REPORT.md]. Those failures are expected until those issues are fixed.