refactor(mini-player): H6 — split MiniPlayer.tsx 820 → 218 LOC across 11 files (#669)

* refactor(mini-player): H6 — extract helpers + constants

Pure code-move: window-size constants, localStorage keys + read helpers,
toMini track shape, initialSnapshot, and fmt(seconds) → utils/miniPlayerHelpers.ts.

MiniPlayer.tsx: 820 → 745 LOC.

* refactor(mini-player): H6 — extract MiniTitlebar + MiniMeta + MiniControls

Three small visual subcomponents move into components/miniPlayer/.
MiniPlayer drops the now-unused Pin/PinOff/Maximize2/X/Play/Pause/
SkipBack/SkipForward lucide icons and the CachedImage import.

MiniPlayer.tsx: 745 → 665 LOC.

* refactor(mini-player): H6 — extract MiniToolbar + useMiniVolumePopover

The whole toolbar (volume button + portaled popover, shuffle, gapless/
crossfade/infinite, queue toggle) moves into MiniToolbar.tsx. The volume
popover open-state + ref/style positioning + outside-click/Escape close
move into the useMiniVolumePopover hook.

MiniPlayer.tsx: 665 → 492 LOC.

* refactor(mini-player): H6 — extract MiniQueue + useMiniQueueDrag

The OverlayScrollArea + queue.map block moves into MiniQueue.tsx. The
PsyDnD wiring (drop-inside emits mini:reorder, drop-outside emits
mini:remove, reorder math collapsing same-position + adjusting for shift)
moves into the useMiniQueueDrag hook.

MiniPlayer.tsx: 492 → 346 LOC.

* refactor(mini-player): H6 — extract useMiniSync + useMiniWindowSetup + useMiniKeyboardShortcuts

Three more hooks pull the remaining side-effect islands out of MiniPlayer:
  - useMiniSync owns mini:ready emit on mount + focus, plus the
    mini:sync / audio:progress / audio:ended listeners. The hidden-window
    visibility ref that gates progress now lives inside the hook.
  - useMiniWindowSetup bundles three small window-bound effects:
    Linux WebKitGTK smooth-scroll, the cold-start expanded-size restore
    when queueOpen=true, and always-on-top reapply on mount + focus.
  - useMiniKeyboardShortcuts moves the keyboard-shortcut bridge wiring.

MiniPlayer.tsx: 346 → 218 LOC.

src/hooks/useMiniQueueDrag.ts

@@ -0,0 +1,107 @@
+import React, { useEffect, useRef, useState } from 'react';
+import { emit } from '@tauri-apps/api/event';
+import { useDragDrop } from '../contexts/DragDropContext';
+import { usePlayerStore } from '../store/playerStore';
+
+interface Args {
+  queueOpen: boolean;
+  miniQueueWrapRef: React.RefObject<HTMLDivElement | null>;
+  queueScrollRef: React.RefObject<HTMLDivElement | null>;
+  fallbackQueueLen: number;
+}
+
+/** Mini-player queue drag/drop wiring. Mirrors QueuePanel's pattern but with
+ *  no external sources — psy-drop on the scroll viewport emits mini:reorder,
+ *  psy-drop outside the wrap emits mini:remove. The reorder math collapses
+ *  same-position drops and adjusts for index-shift after removing the source. */
+export function useMiniQueueDrag({
+  queueOpen, miniQueueWrapRef, queueScrollRef, fallbackQueueLen,
+}: Args) {
+  const { isDragging: isPsyDragging, startDrag, payload: psyPayload } = useDragDrop();
+  const psyDragFromIdxRef = useRef<number | null>(null);
+  const [dropTarget, setDropTarget] = useState<{ idx: number; before: boolean } | null>(null);
+  const dropTargetRef = useRef<{ idx: number; before: boolean } | null>(null);
+
+  const isReorderDrag = isPsyDragging && !!psyPayload && (() => {
+    try { return JSON.parse(psyPayload.data).type === 'queue_reorder'; } catch { return false; }
+  })();
+
+  useEffect(() => {
+    if (!isPsyDragging) {
+      dropTargetRef.current = null;
+      setDropTarget(null);
+    }
+  }, [isPsyDragging]);
+
+  // psy-drop inside the queue strip → mini:reorder.
+  // queueOpen must be in deps because the wrap (and thus queueScrollRef.current)
+  // only mounts when the queue is expanded — without it the ref is null on
+  // first run and the listener never attaches.
+  useEffect(() => {
+    if (!queueOpen) return;
+    const el = queueScrollRef.current;
+    if (!el) return;
+    const onPsyDrop = (e: Event) => {
+      const detail = (e as CustomEvent).detail;
+      if (!detail?.data) return;
+      let parsed: any = null;
+      try { parsed = JSON.parse(detail.data); } catch { return; }
+      const tgt = dropTargetRef.current;
+      dropTargetRef.current = null;
+      setDropTarget(null);
+      if (parsed.type !== 'queue_reorder') return;
+      const fromIdx = parsed.index as number;
+      psyDragFromIdxRef.current = null;
+      const queueLen = usePlayerStore.getState().queue.length || fallbackQueueLen;
+      const insertIdx = tgt
+        ? (tgt.before ? tgt.idx : tgt.idx + 1)
+        : queueLen;
+      if (fromIdx === insertIdx || fromIdx === insertIdx - 1) return;
+      const adjusted = fromIdx < insertIdx ? insertIdx - 1 : insertIdx;
+      if (fromIdx === adjusted) return;
+      emit('mini:reorder', { from: fromIdx, to: adjusted }).catch(() => {});
+    };
+    el.addEventListener('psy-drop', onPsyDrop);
+    return () => el.removeEventListener('psy-drop', onPsyDrop);
+  }, [queueOpen, fallbackQueueLen, queueScrollRef]);
+
+  // Drop outside the mini queue strip → mini:remove (same UX as main QueuePanel).
+  useEffect(() => {
+    if (!queueOpen) return;
+    const onDocPsyDrop = (e: Event) => {
+      const d = (e as CustomEvent<{ data?: string; clientX?: number; clientY?: number }>).detail;
+      if (!d?.data) return;
+      const cx = d.clientX;
+      const cy = d.clientY;
+      if (typeof cx !== 'number' || typeof cy !== 'number') return;
+      let parsed: { type?: string; index?: number } | null = null;
+      try {
+        parsed = JSON.parse(d.data);
+      } catch {
+        return;
+      }
+      if (parsed?.type !== 'queue_reorder' || typeof parsed.index !== 'number') return;
+      const wrap = miniQueueWrapRef.current;
+      if (!wrap) return;
+      const r = wrap.getBoundingClientRect();
+      const inside =
+        cx >= r.left && cx <= r.right && cy >= r.top && cy <= r.bottom;
+      if (inside) return;
+      psyDragFromIdxRef.current = null;
+      dropTargetRef.current = null;
+      setDropTarget(null);
+      emit('mini:remove', { index: parsed.index }).catch(() => {});
+    };
+    document.addEventListener('psy-drop', onDocPsyDrop);
+    return () => document.removeEventListener('psy-drop', onDocPsyDrop);
+  }, [queueOpen, miniQueueWrapRef]);
+
+  return {
+    isReorderDrag,
+    psyDragFromIdxRef,
+    dropTarget,
+    setDropTarget,
+    dropTargetRef,
+    startDrag,
+  };
+}