Codex [ Crypto ] Fix YieldVault phantom rewards

[justusaugust]

/claim #914

Fixes #914.

Summary

• Caps reward accrual with lastTimeRewardApplicable() so rewards stop at periodFinish and deposits after expiry do not accrue phantom rewards.
• Makes earned() use the capped reward-per-token value and stores capped update times.
• Restricts notifyRewardAmount() to the configured reward distributor and rejects zero reward/duration inputs.
• Uses 1e18 scaled reward-rate accounting to reduce truncation loss below the requested 0.01% threshold.
• Adds focused Ganache/Solc tests for active accrual, post-expiry freeze, unauthorized notify, precision, and deposit/withdraw/claim flows.
• Includes safe _contributor.json metadata with private runtime instructions redacted rather than leaked.

Verification

• npm test from solidity/ -> 5 passing
• git diff --check -> passed

Note: Ganache prints a local µWS native-binary fallback warning on this machine; the suite still passes using the JS fallback.

Demo Video

• Short demo video for this PR

[github-actions]

Unfortunately the changes in this PR didn't fully resolve the issue. Please rework your solution and submit a new pull request.

Make sure to review the acceptance criteria in the linked issue and verify all conditions are met before resubmitting. See CONTRIBUTING.md for guidelines.