Fix gas estimation failures and hydration mismatch

[realproject7]

Summary

• Gas estimation: Set explicit gas limits on donate (150k), mint/burn (2M) to bypass MetaMask's broken estimation on Base Sepolia
• Hydration: DeadlineCountdown renders --:--:-- on server, starts countdown after client mount

Test plan

• npm run typecheck passes
• Donate/Buy/Sell flows work without gas errors
• /story/[id] loads without hydration error in console

🤖 Generated with Claude Code

[project7-interns]

T2b APPROVE

All three changes are correct:

1. DeadlineCountdown hydration fix — Standard Next.js pattern: init state as null, compute in useEffect after mount, show --:--:-- placeholder during SSR. Correct fix for time-dependent hydration mismatch.

2. Gas limits (donate 150k, mint/burn 2M) — Reasonable values for these operations. Hardcoded limits are a pragmatic workaround for MetaMask's broken gas estimation on Base Sepolia. Acceptable tradeoff for testnet.

No issues found.

[project7-interns]

Verdict: REQUEST CHANGES

Summary

The gas-limit additions in Donate/Trading look narrowly scoped and the hydration intent is reasonable, but the new DeadlineCountdown implementation introduces a lint-failing React hooks violation. CI is red on this PR for that reason.

Findings

• [medium] The hydration fix triggers react-hooks/set-state-in-effect, so the PR does not pass CI and cannot merge as submitted.
  • File: src/components/DeadlineCountdown.tsx:11
  • Suggestion: Restructure the countdown so the initial placeholder render does not require a synchronous setRemaining(...) inside useEffect (for example, drive display from a mounted/tick state or another pattern that satisfies the hook rule).

Decision

Requesting changes because the PR currently fails the required lint-and-typecheck check on src/components/DeadlineCountdown.tsx:11. Once that is addressed, the remaining changes look appropriately scoped to the reported MetaMask/Base Sepolia issue.

[project7-interns]

Verdict: APPROVE

Summary

The follow-up commit resolves the blocking DeadlineCountdown hook violation without expanding the PR scope. The explicit gas-limit changes remain focused on the MetaMask/Base Sepolia estimation issue, and CI is now green.

Findings

• [info] No remaining blocking findings after f4721b0.
  • File: src/components/DeadlineCountdown.tsx:8
  • Suggestion: None.

Decision

Approving because the prior react-hooks/set-state-in-effect failure has been removed and the required lint-and-typecheck check now passes for PR #153.