feat(primitives): media-editor components, category reorg, perf + type cleanup

Reorganize components into category folders (forms/canvas/overlays/etc.); add the
media-editor headless family (timeline, curve-editor, waveform, crop, color
picker, etc.); apply perf fixes (O(1) collection lookups, plain-object drag
state, gesture-leak teardown, shallowRef color state, rect caching) and replace
source `any` with proper types.

vue/primitives/src/canvas/crop/index.ts

@@ -0,0 +1,26 @@
+export { default as CropRoot } from './CropRoot.vue';
+export { default as CropArea } from './CropArea.vue';
+export { default as CropGrid } from './CropGrid.vue';
+export { default as CropHandle } from './CropHandle.vue';
+export { default as CropOverlay } from './CropOverlay.vue';
+
+export { provideCropContext, useCropContext } from './context';
+export type { CropContext, CropDirection, CropUnits } from './context';
+
+export type { CropAreaProps } from './CropArea.vue';
+export type { CropGridProps } from './CropGrid.vue';
+export type { CropHandleProps } from './CropHandle.vue';
+export type { CropOverlayProps } from './CropOverlay.vue';
+export type { CropRootEmits, CropRootProps } from './CropRoot.vue';
+
+export type { CropBounds, CropHandlePosition, CropRect } from './utils';
+export {
+  CROP_HANDLE_POSITIONS,
+  createRect,
+  fitRectToRatio,
+  minBox,
+  moveRect,
+  normalizeRect,
+  resizeRect,
+  resolveAspectRatio,
+} from './utils';