feat(canvas): restore eraser pressure width, layer quick switch, crop tools and middle-click open

[joshistoast]

Summary

Four interaction behaviors from the legacy frontend were missing from webv2.

• Eraser pressure width. The eraser honours pen pressure for stroke width through a Dynamics switch (on by default), never for opacity, matching legacy; the brush is unchanged.
• Layer navigation and quick switch. Alt+[ / Alt+] cycle all layers in document order (wrapping) when nothing is staged, and keep cycling staged results when it is. Q switches to a bookmarked layer, else the previously selected one; "Bookmark for quick switch" is in the layer context menu. Bookmark and previous selection are transient per engine.
• Reference crop. Aspect-ratio presets constrain the crop (opening Free for a full-frame box, matching a preset only for a saved partial crop), wheel zoom about the cursor, Space or middle-button pan, Fit / Actual size / Zoom buttons, and "Save to Uploads", which uploads the crop as a user image to the gallery's auto-add board independently of Apply.
• Middle-click opens media. An opt-in Gallery setting makes middle-click on image and video tiles open the media in a new tab without selecting it; Canvas middle-button pan is untouched.

Related Issues / Discussions

Follows up the legacy parity audit behind #9803.

QA Instructions

From invokeai/frontend/webv2 (Node 22.14, pnpm 10.12): pnpm check:release passes; no baseline changes (the crop geometry lives in the already-eager core/referenceImage.ts, so the editor's source-owner set is unchanged).

Mock backend (representative profile):

1. Canvas → press E → Properties → Dynamics shows only "Pen pressure affects width". With a pen, light and firm eraser strokes differ in width; the brush still shows both switches.
2. With two or more layers and nothing staged, Alt+] and Alt+[ step the Layers-panel selection and wrap. Right-click a layer → Bookmark for quick switch, select another layer, press Q: the bookmark is selected; Q again returns. Without a bookmark Q toggles the last two selections.
3. Generate panel → reference image → Crop: pick 1:1; the box reshapes about its centre and handle drags keep the ratio. Wheel zooms at the cursor; hold Space or use the middle button to pan; Fit resets. Tab to Apply and press Space: it applies. "Save to Uploads" shows a notice and a new user image appears in the gallery while the dialog stays open.
4. Gallery settings → Thumbnails → "Middle-click opens media in a new tab": off by default; when on, middle-click on a tile opens the full media in a new tab without selecting it.

Review

Material findings resolved: Space was swallowed for every button in the crop dialog (keyboard users could not activate Apply/Cancel with Space); the dialog opened ratio-locked for any image whose full frame matched a preset; the aspect-ratio combobox had no accessible name. Also applied: a selected group now cycles from its first leaf, Save to Uploads honours the auto-add board, and browser tests cover wheel zoom, pan and Space activation. Remaining limitation: "Actual size" assumes the fitted image spans the viewport width; a very tall image capped by the dialog height is slightly off (pre-existing crop-percentage behavior).

Compatibility / Rollout

The new Gallery setting is optional and off by default; bookmark and previous-selection memory are never persisted. No API changes.

Checklist

• The PR has a short but descriptive title, suitable for a changelog
• Meaningful regression coverage added / updated where needed; obsolete tests/code removed
• Persisted-state and API changes include required migrations / compatibility validation
• Relevant performance/efficiency opportunities considered; material claims have evidence
• Material review findings resolved and relevant checks rerun
• Documentation added / updated (if applicable)
• Updated What's New copy (if doing a release after this PR)

🤖 Generated with Claude Code

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