Scan all batch offer roots during fallback resolution

[KeeganEad]

Finding

clawpatch finding fnd_sig-feat-service-b01553a6a4-ceb2_2205db459a: batch offer token-resolution fallback only scanned the latest 10,000 blocks for BatchOfferCreated events. Long-lived active offers created before that window could not be accepted or revoked by contract/tokenId when rare-api direct proof lookup needed root candidates.

Assessment

Confirmed real bug. The fallback is correctness-critical after rare-api direct lookup returns a resolution error, and an active offer can remain fillable past the fixed lookback window. The fix keeps the public SDK API unchanged and preserves the existing 10,000-block query size as an internal pagination chunk.

Fix

• Replace the fixed recent lookback with a backward paginated event scan from latest block to genesis.
• Preserve newest-root-first ordering and root deduplication.
• Continue filtering candidate roots by current fillable status before asking rare-api for proofs.
• Add a unit regression for an active offer event older than the former 10,000-block window.

Validation

• npx vitest run test/unit/sdk/batch-offer.test.ts --config vitest.config.ts
• npm run typecheck
• npm run lint
• clawpatch revalidate --finding fnd_sig-feat-service-b01553a6a4-ceb2_2205db459a --plain -> fixed