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/drawer/constants.ts

@@ -0,0 +1,26 @@
+/** Open/close animation timing, shared by the CSS keyframes and the JS transitions. */
+export const TRANSITIONS = {
+  DURATION: 0.5,
+  EASE: [0.32, 0.72, 0, 1],
+} as const;
+
+/** Drag speed (px/ms) above which a flick closes the drawer regardless of distance. */
+export const VELOCITY_THRESHOLD = 0.4;
+
+/** Default fraction of the drawer that must be swiped away before it closes. */
+export const CLOSE_THRESHOLD = 0.25;
+
+/** How long (ms) dragging stays disabled after scrolling content inside the drawer. */
+export const SCROLL_LOCK_TIMEOUT = 100;
+
+/** Corner radius (px) applied to the scaled background wrapper while open. */
+export const BORDER_RADIUS = 8;
+
+/** Pixels a parent drawer is displaced when a nested drawer opens. */
+export const NESTED_DISPLACEMENT = 16;
+
+/** Top inset (px) used when scaling the background, mimicking a stacked-card look. */
+export const WINDOW_TOP_OFFSET = 26;
+
+/** Class applied to the drawer element while a drag is in progress. */
+export const DRAG_CLASS = 'drawer-dragging';