editor: light WebGPU preview and /editor scene redirect

[ActArtech]

What does this PR do?

Improves the standalone apps/editor local/MCP preview experience:

1. Route compatibility — redirect /editor/:id to /scene/:id so MCP editorUrl links open saved scenes instead of 404.
2. Light preview — scene list opens with ?disable=postFx,outline (existing viewer flags) and forces solid shading when that path is active; scene page exposes a Light preview control.
3. Clearer home banner — home is a blank canvas; saved scenes live under Scenes (wording fix only).

No viewer package API changes; uses existing post-processing disable query flags.

How to test

1. bun run --cwd apps/editor dev (or project equivalent) on port 3002 with a local scene store.
2. Open /editor/<existing-scene-id> — expect redirect to /scene/<id> and the scene loads.
3. Open /scenes — each card links with light-preview query; canvas should stay responsive (post-FX off).
4. On a scene page, click Light preview — URL gains disable flags; shading goes solid.
5. Home / still shows blank editor with link to saved scenes.

Screenshots / screen recording

N/A for core logic (routing + existing viewer flags). Optional: short clip of /editor/id redirect if desired.

Checklist

• I've tested this locally with the editor dev server
• My code follows the existing code style
• I've updated relevant documentation (if applicable)
• This PR targets the main branch

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Note

Low Risk
Scoped to standalone editor routing, preview UX, and an optional Editor prop defaulting to false; no auth or persistence logic changes.

Overview
Adds a light preview path for local WebGPU stability and fixes MCP link routing for the standalone apps/editor app.

Routing: next.config redirects /editor/:id → /scene/:id so MCP editorUrl bookmarks open saved scenes instead of 404.

Light preview: Scene list links include ?disable=postFx,outline. On the scene page, URL query (or safe=1) drives disablePostFx on Editor, solid vs rendered shading via the viewer store, plus a Light preview toolbar button that can re-apply settings or navigate with LIGHT_PREVIEW_QUERY.

Editor package: New optional disablePostFx on Editor / ViewerCanvas, forwarded to Viewer (same effect as ?disable=postFx).

Copy/UI: Home banner clarifies blank canvas vs saved scenes under Scenes; banner layout wraps on small viewports.

^{Reviewed by Cursor Bugbot for commit 003ac55. Bugbot is set up for automated code reviews on this repo. Configure here.}

[ActArtech]

Addressed Bugbot finding L5 in the follow-up commit:

• L5 - light preview now re-applies solid shading when search params change (useSearchParams dependency), so client navigation to ?disable=postFx on the same scene updates correctly.

Same pitfall is noted as L5 in packages/mcp/docs/layout-clearance-error-log.md (layout clearance PR) for future editor/MCP work.

[ActArtech]

Addressed the latest Bugbot finding (N3 / L8):

• When light-preview query flags are cleared, shading restores to rendered so the viewer is not stuck on the solid/light path after client navigation.

Previously we only set solid when flags were present.

[ActArtech]

Addressed the latest Bugbot findings on light preview:

• High - disablePostFx is now threaded SceneLoader → Editor → Viewer, so light preview actually disposes/skips the post-FX pipeline (not only setShading('solid'), which is a no-op when already solid).
• Medium - Light preview is a button that always re-applies solid shading (lightApplyTick), even when the query is already ?disable=postFx,outline after the user changed toolbar shading.

Query flags still toggle disablePostFx; clearing them restores rendered + post-FX.

[cursor]

Cursor Bugbot has reviewed your changes using high effort and found 1 potential issue.

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[cursor]

Preview mode ignores disablePostFx

High Severity

This PR passes disablePostFx into the main editor Viewer, but preview mode renders a second Viewer in previewViewerContent without that prop. On a light-preview scene, opening toolbar Preview turns post-FX back on and can reintroduce the WebGPU instability light preview was meant to avoid.

 

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