fix: 8 image editor bugs found during Docker-based E2E testing

- fix WebP export silently producing PNG when background is non-transparent
- fix autosave not converting blob: URLs inside image-type canvas objects
- fix project load not resetting selection/crop/clipboard state
- fix rotateCanvas not updating object rotation attributes
- fix flipCanvas not negating object rotation attributes
- fix line shadow props overridden by effect spread ordering
- fix "outside" stroke position rendering same as "center"
- add missing pencil tool keyboard shortcut (N)
- remove misleading resample dropdown from image resize dialog
- fix E2E autosave tests for production builds (no Vite dynamic imports)
- fix color picker test case sensitivity (CSS uppercase vs DOM text)
- add 4 unit tests for rotation attribute transforms

apps/web/src/hooks/use-editor-shortcuts.ts

@@ -169,6 +169,16 @@ export function useEditorShortcuts(callbacks?: {
     { preventDefault: true },
   );
 
+  // N - Pencil tool
+  useHotkeys(
+    "n",
+    () => {
+      if (isInputFocused()) return;
+      useEditorStore.getState().setTool("pencil");
+    },
+    { preventDefault: true },
+  );
+
   // E - Eraser tool
   useHotkeys(
     "e",