Flush editor execution before starting sketches

[JordanNoone]

Fixes #13229.

What changed

• Teach the shared deferred callback helper to expose an awaitable flush() that runs pending work immediately and waits for work already in flight.
• Expose that boundary through KclManager.flushPendingEditorExecution().
• Flush direct editor execution before the modeling machine reads the AST or enters sketch mode.

This keeps the normal one-second editor debounce unchanged. The only new ordering constraint is at sketch entry, where the current editor program and Rust scene graph must agree before a sketch ObjectId is created.

Why

The preserved QCC replay for #13229 reproduces the fast sequence 3/3 times and passes a human-paced control 2/2 times. The direct editor edit schedules a debounced settings-only execution, but Start Sketch can create ObjectId(1) first. When the queued execution finally runs, it replaces the Rust scene graph; the next rectangle segment then targets the stale sketch id and fails with Sketch not found: ObjectId(1).

Two deterministic KclManager regressions cover both sides of that ordering boundary: flushing timer-pending editor work and waiting for an editor execution that has already started. They failed before the implementation because the synchronization boundary did not exist; after the change the focused integration suite passes 37/37. The focused utility suite passes 193/193, and TypeScript plus ESLint checks pass.

I also checked draft PR #13605 at head a02bdd3997855e3509e93f03c290eb8d9e324017 as a negative control. It changes modifyAst selection preservation only and does not touch the editor debounce, KclManager, the modeling machine, or Rust scene lifecycle, so it does not cover #13229.

GUI coverage and risk

The QCC adapter discovered the targeted replay against exact origin/main (d2e2a8a5c56024c60d00f11b3a9efd4933aa47a6) and against #13605. A live control replay stopped before browser launch because approved first-party QA authentication was unavailable in this environment. Per the QCC control-first contract, I did not run or claim a fixed GUI replay, so this PR has no new screenshot or trace artifact.

Risk is localized: Start Sketch may now wait for the current direct editor execution instead of racing it. Deferred executions elsewhere retain their existing timer behavior. The remaining uncertainty is visual end-to-end confirmation on an authenticated preview.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated
modeling-app	Ready	Preview	Sep 4, 2026 1:45am UTC