feat(image-editor): PixelForge shell — menu bar, options bar, full PS tool list, tabbed panels

[lyfuci]

Summary

Reshells the image editor around the PixelForge handoff design (claude.ai
Design). The drawing/state engine is unchanged; everything new is the
visual + structural layer that wraps it.

Shell

• CSS grid layout (`.pf-shell`) — 4 rows × 3 cols: menu / options /
  (tools | canvas | right) / status. Tokens scoped to `.pf-root` so
  PixelForge styling can't leak into the rest of the toolbox.
• MenuBar — File / Edit / Image / Layer / View dropdowns; all items
  wired to existing handlers (open, save, undo / redo, rotate, flip,
  duplicate / delete layer, zoom, focus). File menu gets per-format
  export (PNG / JPEG / WebP).
• OptionsBar — context-sensitive per active tool: brush/eraser show
  stroke + color, shape tools show stroke + color, crop shows the
  Enter/Esc hint plus a Clear-crop button when a crop is applied. Stub
  tools render an honest "placeholder" hint.
• ToolsPalette — full 18-tool PS-aligned list, grouped (Selection /
  Painting / Vector+Type / Annotation / Navigation). FG/BG color swatches
  • X / D ⇄ ▣ swap/reset live at the bottom of the rail.
• RightSidebar — three stacked panel groups with tab strips:
  Layers / Channels / Paths · Properties / Info · Adjustments / Navigator.
  Channels / Paths / Info / Navigator render a "coming soon" stub so the
  panel surface is complete without lying about functionality.
• StatusBar — denser, PixelForge-styled, surfaces the current tool +
  document dimensions + zoom.

Tools

Functional (work end-to-end): Move (V), Crop (C), Eyedropper (I),
Brush (B), Eraser (E), Type (T), Rectangle / Ellipse / Line / Arrow,
Mask, Mosaic, Zoom (Z).

Stub (palette + tooltip + shortcut, but the tool action shows a
toast and leaves state unchanged): Marquee (M), Lasso (L), Magic Wand
(W), Spot Healing (J), Clone Stamp (S), History Brush (Y), Gradient /
Paint Bucket (G), Dodge (O), Pen (P), Hand (H). These need either a
selection model (marquee/lasso/wand), a flood-fill primitive (bucket),
or a vector-path layer (pen) — substantial follow-up PRs.

Cleanup

• Dropped the old `TopActionBar` (its actions are now in the menu bar).
• `STUB_TOOLS` lives in `tool-meta.ts` so `ToolsPalette.tsx` only exports
  components (react-refresh requirement).

Branched from `main` (not stacked).

Test plan

• Open an image — shell renders with menu bar, options bar, tool rail, canvas, panels, status bar.
• Click each menu — File/Edit/Image/Layer/View dropdowns open; ESC closes.
• File > Export as PNG / JPEG / WebP — each downloads with the correct extension and MIME.
• Click Brush — options bar shows stroke + color; drawing works.
• Click Crop, drag a rect, press Enter — crop applies; the options bar shows "Clear crop" when a crop is active.
• Click a stub tool (Lasso, Wand, Pen, etc.) — toast appears, no tool change.
• Press M / L / W / J / S / Y / G / O / P / H — toast appears for each.
• Press B / E / T / I / C / Z / V — tool actually switches.
• Right column tabs (Layers / Channels / Paths) switch; Channels / Paths show stub copy.
• Same for Properties / Info and Adjustments / Navigator groups.
• Save .json project → reload → state survives.

🤖 Generated with Claude Code