The tilemap panel gains Fill and Pick: Fill floods the connected cells of the active layer that carry the same tile (edge neighbours only, bounded by the grid) as one undo step, Pick takes the tile of the clicked cell on the active layer, and holding Alt picks while any tool is active (#133)

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tools/lib/harness.mjs

@@ -43,6 +43,7 @@ const KEYS = {
   ArrowRight: { key: 'ArrowRight', code: 'ArrowRight', windowsVirtualKeyCode: 39 },
   ArrowDown: { key: 'ArrowDown', code: 'ArrowDown', windowsVirtualKeyCode: 40 },
   Delete: { key: 'Delete', code: 'Delete', windowsVirtualKeyCode: 46 },
+  Alt: { key: 'Alt', code: 'AltLeft', windowsVirtualKeyCode: 18 },
   a: { key: 'a', code: 'KeyA', windowsVirtualKeyCode: 65 },
   c: { key: 'c', code: 'KeyC', windowsVirtualKeyCode: 67 },
   d: { key: 'd', code: 'KeyD', windowsVirtualKeyCode: 68 },