fix/prevent expired task from been approved

[EmmyKay0026]

Description

Prevents proofs submitted after a task’s expiration deadline from transitioning to APPROVED or generating a reward payout.

This change introduces a centralized proof approval eligibility rule and applies it consistently across:

• Automatic verification
• Admin proof review
• Validator quorum resolution
• Atomic completion-slot claiming

The task deadline is evaluated against proof.createdAt using an inclusive cutoff:

• Proofs submitted at or before task.expiresAt remain eligible, even if the task expires before finalization.
• Proofs submitted after task.expiresAt are forced to REJECTED.
• New submissions are blocked when the deadline has passed, even if the expiry sweep has not yet changed the task from ACTIVE to EXPIRED.

Fixes #55

Type of Change

• Bug fix (non-breaking change fixing an issue)
• New feature (non-breaking change adding functionality)
• Breaking change (fix or feature that breaks existing behaviour)
• Refactor (code change that neither fixes a bug nor adds a feature)
• Test (adding or updating tests)
• Docs (documentation-only changes)
• Chore (tooling, CI/CD, build process)

How Has This Been Tested?

• npm test passes
• npm run build succeeds
• Manual testing steps described below

Manual/targeted verification performed:

• Verified automatic verification rejects post-deadline proofs.
• Verified the worker rechecks eligibility before approval and payout.
• Verified admin approval is forced to rejection for post-deadline proofs.
• Verified an approving validator quorum is forced to rejection for post-deadline proofs.
• Verified proofs submitted before or exactly at the deadline remain eligible after the expiry sweep.
• Verified stale ACTIVE tasks with a past deadline reject new submissions.
• Verified no reward payout record is created for blocked proofs.
• Ran the verification service, verification worker, validator service, and proof-to-reward integration suites successfully.
• Ran the new admin-review and stale-expiry route tests successfully.
• Ran ESLint and Prettier successfully.

The complete proof route suite currently has an unrelated ECONNRESET failure on its first unauthenticated request. The remaining route tests pass, including all tests added by this change.

Checklist

• My code follows the project's coding conventions
• I have added tests that prove my fix/feature works
• New and existing tests pass locally
• I have updated the documentation if needed
• My changes generate no new warnings or errors

Additional Context

The cutoff is based on the proof submission timestamp rather than the finalization timestamp. This prevents asynchronous verification or review latency from invalidating legitimate work submitted while the task was still open.

The completion-slot database update also enforces the task deadline and allowed task states, providing defense in depth against races or stale expiry-sweep state.

[cybermax4200]

Fix the workflow