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/display/scroll-area/ScrollAreaScrollbarHover.vue

@@ -0,0 +1,67 @@
+<script lang="ts">
+import type { PrimitiveProps } from '../../internal/primitive';
+
+export interface ScrollAreaScrollbarHoverProps extends PrimitiveProps {
+  orientation?: 'horizontal' | 'vertical';
+  forceMount?: boolean;
+}
+</script>
+
+<script setup lang="ts">
+import { onScopeDispose, ref } from 'vue';
+import { useEventListener, useForwardExpose } from '@robonen/vue';
+import { Presence } from '../../utilities/presence';
+import ScrollAreaScrollbarAuto from './ScrollAreaScrollbarAuto.vue';
+import { useScrollAreaRootContext } from './context';
+
+defineOptions({ inheritAttrs: false });
+
+withDefaults(defineProps<ScrollAreaScrollbarHoverProps>(), {
+  orientation: 'vertical',
+});
+
+const ctx = useScrollAreaRootContext();
+const { forwardRef } = useForwardExpose();
+const visible = ref(false);
+let hideTimer: ReturnType<typeof setTimeout> | null = null;
+
+function clearTimer() {
+  if (hideTimer !== null) {
+    globalThis.clearTimeout(hideTimer);
+    hideTimer = null;
+  }
+}
+
+function onEnter() {
+  clearTimer();
+  visible.value = true;
+}
+function onLeave() {
+  clearTimer();
+  hideTimer = globalThis.setTimeout(() => {
+    visible.value = false;
+  }, ctx.scrollHideDelay.value);
+}
+
+// Re-attaches automatically when the scroll-area element changes; SSR-safe
+// (the getter resolves to `undefined` on the server).
+useEventListener(() => ctx.scrollArea.value, 'pointerenter', onEnter);
+useEventListener(() => ctx.scrollArea.value, 'pointerleave', onLeave);
+
+onScopeDispose(clearTimer);
+</script>
+
+<template>
+  <Presence :present="forceMount || visible">
+    <ScrollAreaScrollbarAuto
+      :ref="forwardRef"
+      v-bind="$attrs"
+      :orientation="orientation"
+      :as="as"
+      :data-state="visible ? 'visible' : 'hidden'"
+      force-mount
+    >
+      <slot />
+    </ScrollAreaScrollbarAuto>
+  </Presence>
+</template>