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/utilities/visually-hidden/index.ts

@@ -0,0 +1,6 @@
+export { default as VisuallyHidden } from './VisuallyHidden.vue';
+export type { VisuallyHiddenProps } from './VisuallyHidden.vue';
+export { default as VisuallyHiddenInput } from './VisuallyHiddenInput.vue';
+export type { VisuallyHiddenInputProps } from './VisuallyHiddenInput.vue';
+export { default as VisuallyHiddenInputBubble } from './VisuallyHiddenInputBubble.vue';
+export type { VisuallyHiddenInputBubbleProps } from './VisuallyHiddenInputBubble.vue';