fix: resolve 41 bugs and wire 21 unimplemented features in image editor

Canvas rendering:
- Fix Konva filter application order (filters before cache)
- Implement 6 missing filters (motionBlur, radialBlur, surfaceBlur, vignette, grain, sharpen)
- Implement exposure, vibrance, warmth adjustments as custom Konva filters
- Apply layer blend modes via globalCompositeOperation
- Apply object effects (drop shadow, outer glow, stroke) to all shapes
- Mount SmartGuidesOverlay during move tool drag
- Clip pixel grid to visible viewport (200-line cap for performance)

Store logic:
- resizeImage now scales all objects proportionally (points, radii, fontSize)
- rotate/flip/trim handle line/arrow points arrays and center-based objects
- applyCrop creates cropped source image via offscreen canvas
- invertSelection creates mask from bounds when no mask exists
- cutObjects uses single atomic set() to prevent race conditions
- sendToBack respects layer ordering in multi-layer documents
- Add batchNudge() and commitHistory() for undoable nudge operations
- Add updateLayerThumbnail() method

Tool hooks:
- Fix clone stamp/dodge/burn perf (toDataURL only on mouseUp, not every move)
- Fix magic wand zoom/pixelRatio with explicit stage.toCanvas() viewport
- Fix eyedropper sampling with unzoomed canvas export
- Fix selection tool stale closure via isDrawingRef
- Implement polygonal lasso (click-to-place vertices, double-click to close)
- Implement selection subtract mode (geometric and mask-based)
- Implement gradient live preview during drag
- Fix transform/move tool to persist changes and handle ellipse/polygon/star

UI wiring:
- Mount rulers and guidelines in editor page
- Wire histogram with live canvas imageData
- Wire autosave recovery with blob-to-dataURL conversion
- Wire fill dialog to Shift+Backspace shortcut
- Wire eyedropper and transform options to options bar
- Fix history panel undo/redo button reactive state via useSyncExternalStore
- Fix layer row name click to select layer (timer-based click/dblclick)
- Fix zoom animation coordinate drift with progressive store sync
- Fix copy merged to use Konva stage composite export

Tests:
- 49 new unit tests (store fixes + konva filters)
- 8 new E2E test files with 39 test cases

playwright.editor.config.ts

@@ -9,7 +9,7 @@ export default defineConfig({
   retries: 0,
   reporter: "html",
   use: {
-    baseURL: "http://localhost:1351",
+    baseURL: `http://localhost:${process.env.EDITOR_TEST_PORT ?? "1349"}`,
     trace: "retain-on-failure",
     screenshot: "only-on-failure",
     viewport: { width: 1440, height: 900 },