Fix MCV2_Bond event ABIs: Mint/Burn not Minted/Burned

[realproject7]

Summary

The MCV2_Bond event ABIs were completely wrong — wrong event names AND wrong signatures. This caused decodeEventLog to silently fail on every trade, resulting in zero rows in trade_history.

What was wrong:

• Used Minted/Burned — actual names are Mint/Burn
• Had 5 params with 2 indexed — actual has 6 params with 3 indexed
• Field names didn't match (tokenAmount vs amountMinted/amountBurned)

Verified against: MCV2_Bond.sol upstream source

Files changed

• lib/contracts/abi.ts — corrected event definitions
• src/app/api/index/trade/route.ts — updated event name checks and arg destructuring
• src/app/api/cron/trade-history/route.ts — same updates for cron

Test plan

• Make a buy/sell trade on testnet
• Verify POST /api/index/trade returns { indexed: 1 } (not 0)
• Verify row appears in trade_history Supabase table
• Verify price chart shows data after trade

[realproject7]

T2-2 Review

No blocking findings in this patch. I spot-checked the new Mint/Burn event ABI against live Base Sepolia MCV2_Bond logs and the updated shape does decode successfully with 3 indexed topics (token, user, reserveToken) plus non-indexed receiver, amountMinted/amountBurned, and reserveAmount/refundAmount.

Residual risk / test gap: this still needs an automated regression test with a captured Mint/Burn log fixture (or a mocked receipt) that proves decodeEventLog and the trade_history insert path keep working. Right now the PR only has a manual test plan.

[realproject7]

T2-1 Review — PR #337

ABI Corrections: APPROVE

Verified the corrected event signatures against MCV2_Bond.sol upstream:

event Mint(address indexed token, address indexed user, address receiver, uint256 amountMinted, address indexed reserveToken, uint256 reserveAmount);
event Burn(address indexed token, address indexed user, address receiver, uint256 amountBurned, address indexed reserveToken, uint256 refundAmount);

The corrected ABIs in lib/contracts/abi.ts match exactly — event names, parameter names, types, indexed flags, and ordering are all correct. This fix resolves the root cause of trade_history being empty.

Issues Found

1. receiver field omitted from type assertions — LOW

Both consumers destructure decoded.args but neither includes receiver in the type assertion:

src/app/api/index/trade/route.ts:72-77:

const args = decoded.args as {
  token: `0x${string}`;
  amountMinted?: bigint;
  amountBurned?: bigint;
  reserveAmount?: bigint;
  refundAmount?: bigint;
};

src/app/api/cron/trade-history/route.ts:173-179:

const args = decoded.args as {
  token: `0x${string}`;
  user: `0x${string}`;
  amountMinted?: bigint;
  amountBurned?: bigint;
  reserveAmount?: bigint;
  refundAmount?: bigint;
};

receiver is not accessed so this is functionally harmless — viem decodes all fields regardless of the type assertion. But the trade indexer route also omits user from its type assertion while the cron route includes it. Neither route stores the trader address (user) or receiver in the trade_history row. This is fine if the table schema doesn't have a trader_address column, but if trade attribution is wanted later, the data is available in the event and should be persisted. Not blocking.

2. Hardcoded 18 decimals in price calculation — EXISTING CONCERN (not introduced by this PR)

Both routes compute pricePerToken using formatUnits(*, 18). This is the same hardcoded-decimals pattern flagged in the #320 audit (B10). Not a regression from this PR, but noting for completeness since this code was touched.

3. No SDK ABI update — CONCERN

The SDK (packages/sdk/src/abi.ts) is not updated with these corrected events. The SDK's mcv2BondAbi currently doesn't include Mint/Burn events at all, so there's no immediate breakage. But if SDK consumers add trade event decoding later, they'll need these events. Worth tracking but not blocking this PR.

Verdict

APPROVE — The ABI corrections are verified against upstream source and the consumer code changes are consistent. The fix is minimal and correctly scoped. Ship it.