[u7-u7]

Problem

scroll-to and targeted wheel check cancellation/deadline before/after target/geometry awaits. If a CDP reply such as DOM.resolveNode never arrives, the second check is unreachable: the tool remains pending after timeout_ms or signal abort. Awaiting object-group cleanup can also hold a completed result.

Change

• Reuse the existing input-readiness reply race for target lookup, frame graph and geometry commands.
• Guard queued CDP dispatch against cancellation/deadline where supported.
• Dispatch object-group cleanup without awaiting acknowledgment; release again if a late node resolution allocates a handle after cleanup. Consume late replies without continuing the operation.
• Handler-level regressions for timeout, abort, late replies, unresponsive cleanup and queued dispatch in both tools.

Scope: target/geometry and object cleanup only. Does not cancel commands already delivered to Chrome, change wheel input-ack/overlay lifecycle, or claim every external phase is bounded. Cleanup remains best-effort if transport never responds.

Validation

Base6c9d523755b5607b4038b619e35b4e1f814d7838 with new tests:8 failed/88 passed. Fixed:

• Focused scroll/wheel vitest:96 passed.
• Complete extension vitest:3318 passed/278 skipped (190 files passed/37 skipped).
• Extension tsc --noEmit:passed.
• Biome on all5 changed files and git diff --check:passed.

Real handlers with controlled CDP promises in repository happy-dom tests. Not run:live Chrome/browser evaluation,Rust workspace tests,full monorepo lint. Skipped tests are not counted as passes. Dependency install populated tools but wrapper reported unapproved @parcel/watcher build script; script not approved, installed test/typecheck binaries invoked directly.

All-state PR dedupe checked:input-readiness/wheel-burst changes #261/#480 do not cover pending geometry replies; process-group #511 unrelated.

AI-assisted implementation and automated tests/review. Draft for maintainers; no human-review claim.