fix(sim): track swap output token in wallet-balance snapshots

[dglowinski]

Problem

Wallet-receiving swaps (withdraw / redeem / wallet swaps) transfer the swapped-in token to the wallet via verifyAmountMinAndTransfer(asset, …). The wallet-balance snapshot discovery in buildSimulationBatch only covered touched-vault underlyings, required-approval (debited) tokens, and claim/unlock tokens — so the swap output token was never snapshotted in simulatedWalletBalances. As a result the output stayed invisible to consumers (e.g. a withdraw → swap-to-PT-AUSD feeding a multiply showed a 0 available balance), and to later wallet-sourced batch operations. extractBalanceRequirements only covers debited tokens, so it doesn't help here.

Fix

Add collectSwapWalletBalanceTokens(batch) — mirroring collectClaimWalletBalanceTokens — that decodes the verifyAmountMinAndTransfer verifier item and adds its asset to the snapshotted wallet tokens, wired into buildSimulationBatch next to the claim-token loop.

Scope: the transferMin (wallet-receive) verifier only. The deposit/skim verifier variants land output into a vault (a different balance) and are out of scope.

Test

Adds simulateTransactionPlan tracks swap-verifier wallet output tokens. Full suite green (322 tests).

🤖 Generated with Claude Code

[LeonardEulerXYZ]

Reviewed head: 504e268

Verdict: Approved

Scope reviewed:

• packages/euler-v2-sdk/src/services/executionService/simulate.ts
• packages/euler-v2-sdk/test/simulate.test.ts

What changed:

• Simulation wallet-balance discovery now decodes SwapVerifier verifyAmountMinAndTransfer(address,address,uint256,uint256) calls and includes the transfer asset in per-layer wallet balanceOf(owner) snapshots.
• Added a regression test proving a transferMin swap verifier call causes the output token to be included in wallet-balance reads.

Evidence and validation:

• Full PR diff inspected against origin/development at base 82feb80.
• Active issue comments, formal reviews, and inline review comments inspected; there were no existing Leonard or bot comments to update or clean up.
• Security/supply-chain sweep over the diff: no dependency, lockfile, workflow, package-export, network, secret, env, install-script, or generated-client changes; only simulation code and tests changed.
• ABI fixture check after build: verifyAmountMinAndTransfer(address,address,uint256,uint256) selector resolves to 0xcbe0a971, the encoded calldata decodes back to verifyAmountMinAndTransfer, and arg0 is the transfer asset being added to the wallet-balance token set.
• pnpm --filter @eulerxyz/euler-v2-sdk test -- simulate.test.ts passed. Vitest executed the package suite: 26 files / 322 tests passed.
• pnpm --filter @eulerxyz/euler-v2-sdk typecheck passed.
• pnpm --filter @eulerxyz/euler-v2-sdk build passed.
• pnpm --filter @eulerxyz/euler-v2-sdk lint exited 0; it reported pre-existing warnings in unrelated src/utils/* files, not in this PR's changed files.
• gh pr checks reported no checks on the branch.

Scalability / maintainability hygiene pass:

• Started from the intended consumer behavior: Euler Lite stitches simulatedWalletBalances and surfaces insufficientWalletAssets; missing the swap output token means a wallet-receiving swap can be invisible to later wallet-sourced operations and wallet delta display.
• Sibling wallet-balance discovery paths in this module were checked: touched vault assets, required wallet-balance tokens, operation-provided walletBalanceTokens, claim reward tokens, and rEUL unlock tokens. This patch fits the existing reusable discovery pattern rather than duplicating display logic downstream.
• Sibling swap verifier flows were checked: TransferMin is the wallet-output verifier; SkimMin deposits/skims into vaults and remains covered by touched-vault assets; DebtMax repays debt and remains outside wallet-output tracking. I did not find a missed parallel transfer-output flow.
• Cross-repo consumer pass: current Euler Lite development consumes simulateTransactionPlan, simulatedWalletBalances, and insufficientWalletAssets in composables/useTxBatch.ts; this SDK-side fix is the narrow producer-side abstraction needed by that consumer. No Lite code change is required, aside from normal SDK version uptake/release sequencing.

Bot/reviewer feedback:

• No active CodeRabbit/other bot comments or prior Leonard comments were present on the PR at review time.

Screenshots:

• Not applicable; this is SDK simulation logic with no direct UI surface changed in the PR.

Comment lifecycle: none found; no Leonard comments or inline review comments needed cleanup.

[LeonardEulerXYZ]

Reviewed head: 3796c15

Verdict: Approved

Scope reviewed:

• packages/euler-v2-sdk/src/services/executionService/simulate.ts
• packages/euler-v2-sdk/test/simulate.test.ts

What changed:

• Simulation wallet-balance discovery now decodes SwapVerifier verifyAmountMinAndTransfer(address,address,uint256,uint256) verifier calls and includes the transfer asset in the wallet balanceOf(owner) snapshot token set.
• Added a regression test covering the transferMin wallet-output case.

Validation performed:

• pnpm install --frozen-lockfile from a fresh clone
• pnpm test -- simulate.test.ts -t "simulateTransactionPlan tracks swap-verifier wallet output tokens" — passed; Vitest executed the package test set, 26 files / 347 tests passed
• pnpm typecheck — passed
• pnpm build — passed
• pnpm lint — exit 0; reported pre-existing warnings outside this PR’s touched files (src/utils/*)
• git diff --check origin/main...HEAD — clean
• malicious/supply-chain sweep over the diff — no package, lockfile, workflow, dependency, secret, network, env, or script-surface changes found

Scalability / maintainability hygiene pass:

• Searched sibling simulation and transaction paths for walletBalanceTokens, simulatedWalletBalances, verifyAmountMinAndTransfer, and swapVerifierAbi usage.
• The change is correctly centralized in simulation wallet-balance discovery rather than patching a downstream consumer display path.
• Existing explicit walletBalanceTokens producers for rewards/rEUL remain compatible; this PR covers the missing implicit verifier-derived transfer token.
• Deposit/skim verifier variants intentionally remain out of scope because they land output into a vault, not directly into the wallet snapshot being fixed here.

Bot / reviewer feedback:

• No active CodeRabbit or other bot comments were present to verify/refute.
• Previous Leonard approval was attached to stale head 504e2682...; this review supersedes it for the current head.

Screenshots:

• Not applicable: SDK simulation logic/test-only change, no user-visible UI was exercised.

No blocking correctness, API-compatibility, generated-package, dependency, build, type-safety, protocol-integration, or downstream consumer risks found.