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/overlays/hover-card/HoverCardContent.vue

@@ -0,0 +1,42 @@
+<script lang="ts">
+import type { HoverCardContentImplEmits, HoverCardContentImplProps } from './HoverCardContentImpl.vue';
+
+/**
+ * The floating panel that holds the previewed content. It is positioned against
+ * the trigger and is mounted only while the card is open (gated by `Presence`),
+ * unless `forceMount` is set so you can drive enter/exit animations yourself.
+ */
+export interface HoverCardContentProps extends HoverCardContentImplProps {
+  /** Keep mounted for CSS exit animations. */
+  forceMount?: boolean;
+}
+
+export type HoverCardContentEmits = HoverCardContentImplEmits;
+</script>
+
+<script setup lang="ts">
+import HoverCardContentImpl from './HoverCardContentImpl.vue';
+import { Presence } from '../../utilities/presence';
+import { useForwardExpose } from '@robonen/vue';
+import { useHoverCardContext } from './context';
+
+const { forceMount = false, ...contentProps } = defineProps<HoverCardContentProps>();
+const emit = defineEmits<HoverCardContentEmits>();
+const ctx = useHoverCardContext();
+const { forwardRef } = useForwardExpose();
+</script>
+
+<template>
+  <Presence :present="ctx.open.value" :force-mount="forceMount">
+    <HoverCardContentImpl
+      v-bind="contentProps"
+      :ref="forwardRef"
+      @escape-key-down="emit('escapeKeyDown', $event)"
+      @pointer-down-outside="emit('pointerDownOutside', $event)"
+      @focus-outside="emit('focusOutside', $event)"
+      @interact-outside="emit('interactOutside', $event)"
+    >
+      <slot />
+    </HoverCardContentImpl>
+  </Presence>
+</template>