fix(lending): accept --amount max sentinel in supply/borrow/repay/withdraw

[Hiksang]

Summary

defi --chain <X> lending withdraw --asset <T> --amount max --broadcast failed with Cannot convert max to a BigInt because lending.ts called BigInt(opts.amount) directly. token.ts approve has supported the "max" sentinel since the SSOT 7.x baseline; lending lagged.

Reproduced live on Mantle Aave V3 during the 2026-05-07 multi-chain broadcast verification — the workaround was to call lending position first to read the exact balance, then pass it back as --amount <integer>. That extra round-trip is exactly what --amount max was meant to spare the user.

Fix

ts/packages/defi-cli/src/commands/lending.ts:

• Adds parseAmount(s) helper that maps "max" / "all" / "ALL" (case-insensitive) to viem.maxUint256, otherwise defers to BigInt(s) so every existing wei/integer input is preserved verbatim.
• Applies the helper in all four state-changing handlers — supply, borrow, repay, withdraw — for symmetry with the Aave V3 / Compound V2 sentinel convention (type(uint256).max = "repay all" / "withdraw all").
• Updates --amount help strings to mention 'max'.

Adapter compatibility (no changes needed)

Adapter	uint256.max behaviour
aave_v3.ts	Already logs "Withdraw all (auto-max)" in the description — confirmed live during the 2026-05-07 verification when an explicit integer amount equal to the user's balance was supplied.
compound_v2.ts	Forwards redeemUnderlying(amount) verbatim to the cToken; uint256.max is the standard Compound V2 sentinel for "withdraw all".

Test plan

• 12 new tests in commands/lending.test.ts (4 subcommands × 3 cases each):
  • --amount max → maxUint256 in tx description
  • --amount ALL → same (case-insensitive)
  • --amount 12345 → stays a literal bigint
• vi.mock stubs createLending() so the tests run offline. The stub's build* methods echo params.amount back into the description, making the parser's round-trip observable end-to-end through the Executor's dry-run preview.
• pnpm -C ts -r build — clean.
• pnpm -C ts -r lint — 3 packages, tsc --noEmit clean.
• pnpm -C ts -r test — defi-core 32/32, defi-protocols 39/39, defi-cli 87/87 (was 75; +12 lending tests).
• Live broadcast verification of the new max path is intentionally deferred — the parser fix is unit-test-covered and the adapter side-effects of uint256.max are unchanged from prior on-chain behaviour.

Out of scope

A second bug surfaced during the same broadcast verification: Compound V2 (Venus) on BNB rejects native BNB (0x0 sentinel) because the adapter's resolveVtoken() looks up by underlying() and vBNB.underlying() reverts. That's a separate, larger fix tracked in a follow-up PR.

🤖 Generated with Claude Code