fix(items): don't clobber a same-commit settled flag (cached-model race)

[wass08]

What does this PR do?

Fixes the effect-ordering race behind tonight's slow office bake: a cached item model mounts in the same commit as ModelWithRetry, child effects run first (settled=true), and the wrapper's mount effect then stomped it back to false permanently. The item renders and exports fine — the artifact was complete — but its dirty mark never clears, so scene-ready waits out the full sceneReadyMaxWaitMs cap and the bake page falsely reports the loaded items as skipped.

Only the bake worker hits this (shared warm HTTP context → synchronous cached mounts); every fresh-browser local test loads via suspense and settles after the wrapper's effect, which is why it validated clean locally.

The settled flag is now URL-stamped: unsettleForUrl is a no-op when the flag is already settled for the same URL (the cached same-commit case), and still resets on a genuine model swap (the URL-keyed remount keeps the retry-budget reset).

How to test

1. bun dev, /bake/demo_office?disable=postFx,draw — settles organically (~2.5s), full artifact, skippedItems absent.
2. Real proof post-merge: a warm office-scene bake on the worker should settle in seconds instead of waiting the full 240s cap, with no false skips.

Screenshots / screen recording

N/A.

Checklist

• I've tested this locally with bun dev
• My code follows the existing code style (run bun check to verify)
• I've updated relevant documentation (if applicable)
• This PR targets the main branch

🤖 Generated with Claude Code

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Note

Medium Risk
Touches scene-ready / bake gating via itemModelSettled in ItemSystem; behavior change is narrow but timing-sensitive for headless exports.

Overview
Fixes a React effect-ordering bug where cached GLBs could render correctly but never clear the item “settled” dirty mark, so headless bakes waited until sceneReadyMaxWaitMs and falsely reported skips.

ItemRenderer replaces the boolean setSettled callback with a SettleControl that writes itemModelSettled together with itemModelSettledUrl. ModelWithRetry calls unsettleForUrl(url) on mount instead of always forcing unsettled — it is a no-op when the flag is already settled for that same URL (child ModelRenderer effect runs first on synchronous cache hits). Genuine asset swaps still reset because the component is keyed by URL.

settle(url) is used when the model resolves, on terminal load failure, and for room-clear preview.

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Remount preserves stale settled flag

High Severity

When ModelWithRetry remounts (e.g. node.asset.src key change) but resolveCdnUrl yields the same URL, unsettleForUrl returns early if itemModelSettled is already true for that URL. Stale userData on the parent group can survive from a prior terminal skip or load, so ItemSystem may clear the dirty mark while the GLB is still loading and scene-ready can fire too early for bakes.

 

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