refactor(lib): move generic hooks, DnD engine, shortcut contract to lib

Continue M4 lib/ de-flattening with domain-agnostic infra:
- lib/hooks/: 9 pure generic hooks (useDebouncedValue, useIsMobile,
  useLongPressAction, useRangeSelection, useResizeClientHeight,
  useWindowVisibility, useSystemPrefersDark, useVirtualizerScrollMargin,
  useRemeasureGridVirtualizer) — all PURE (only react/zustand/tanstack deps).
- lib/dnd/DragDropContext.tsx: the generic mouse-event DnD engine (WebKitGTK
  HTML5-DnD workaround, ~24 importers, self-contained) — empties src/contexts/.
- lib/shortcuts/: shortcutActions + shortcutTypes (the action-id + binding
  contract; registry/dispatch/bindings stay app-level and import the contract,
  app->lib direction).

useWindowFullscreenState deliberately NOT moved — kept in hooks/ as app-shell
per the handoff iron-rule list (overrides its pure-helper appearance).

Pure move via deep @/lib/* specifiers. tsc 0, lint 0/0, full suite 319 files /
2353 tests green.

src/config/shortcutActionRegistry.ts

@@ -8,7 +8,7 @@ import { usePlayerStore } from '../store/playerStore';
 import { usePreviewStore } from '../store/previewStore';
 import { useLyricsStore } from '../store/lyricsStore';
 import { showToast } from '../utils/ui/toast';
-import type { ActionContext, ShortcutSlot, ShortcutActionMeta } from './shortcutTypes';
+import type { ActionContext, ShortcutSlot, ShortcutActionMeta } from '@/lib/shortcuts/shortcutTypes';
 
 let cliPremuteVolume: number | null = null;
 

src/config/shortcutActions.ts

@@ -1,74 +0,0 @@
-// ─── Shortcut-action subsystem ───────────────────────────────────────────────
-//
-// Barrel + contract reference. Split into:
-//   shortcutTypes.ts            — shared types
-//   shortcutActionRegistry.ts   — SHORTCUT_ACTION_REGISTRY + action id types
-//   shortcutDispatch.ts         — runtime + CLI dispatch
-//   shortcutBindings.ts         — derived in-app / global binding tables
-// Existing call sites import from this module unchanged.
-//
-// ── The contract ─────────────────────────────────────────────────────────────
-//
-// Every shortcut action is one entry in `SHORTCUT_ACTION_REGISTRY`, keyed by a
-// stable id (`ShortcutAction`). Its `ShortcutActionMeta` declares which of three
-// independent *trigger surfaces* the action is exposed on — an action may opt
-// into any combination:
-//
-//   • inApp?   — bindable to a keyboard chord while the MAIN window is focused.
-//                Presence of the `inApp` slot makes the id a `KeyAction`; the
-//                slot's `defaultBinding` is the out-of-box chord (or null =
-//                unbound), `hidden` keeps it out of the Settings UI list.
-//                Surfaced via IN_APP_SHORTCUT_ACTIONS / DEFAULT_IN_APP_BINDINGS;
-//                matched at runtime by `shortcuts/runtime.ts`.
-//   • global?  — registrable as an OS-LEVEL global hotkey (fires even when the
-//                app is unfocused). Presence makes the id a `GlobalAction`;
-//                surfaced via GLOBAL_SHORTCUT_ACTIONS / DEFAULT_GLOBAL_SHORTCUTS.
-//                `isGlobalShortcutActionId` is the runtime guard.
-//   • runInMiniWindow — whether the action may run when triggered FROM the
-//                mini-player window. `canRunShortcutActionInMiniWindow` gates
-//                cross-window `shortcut:run-action` events.
-//
-// Two extra, surface-independent fields:
-//   • cli?     — exposes the action to `psysonic --player <verb>`. No-arg CLI
-//                verbs are auto-collected and dispatched by
-//                `executeCliPlayerCommand`; arg-carrying commands (play-id,
-//                seek-relative, set-volume, set-repeat, set-rating-current)
-//                are handled explicitly there.
-//   • run(ctx) — the handler. `ctx.previewPolicy` ('stop' | 'ignore') decides
-//                whether an active track-preview is interrupted: media keys
-//                pass 'ignore', explicit UI / in-app keys pass 'stop'.
-//
-// Dispatch entry points: `executeRuntimeAction` (any trigger surface) and
-// `executeCliPlayerCommand` (CLI). `isShortcutAction` validates an arbitrary
-// string against the registry.
-
-export type {
-  TranslateLike,
-  ShortcutSlot,
-  ActionContext,
-  CliContext,
-  ShortcutActionMeta,
-} from './shortcutTypes';
-
-export {
-  SHORTCUT_ACTION_REGISTRY,
-  type ShortcutAction,
-  type KeyAction,
-  type GlobalAction,
-} from './shortcutActionRegistry';
-
-export {
-  isShortcutAction,
-  isGlobalShortcutActionId,
-  canRunShortcutActionInMiniWindow,
-  executeRuntimeAction,
-  executeCliPlayerCommand,
-  type RuntimeAction,
-} from './shortcutDispatch';
-
-export {
-  IN_APP_SHORTCUT_ACTIONS,
-  GLOBAL_SHORTCUT_ACTIONS,
-  DEFAULT_IN_APP_BINDINGS,
-  DEFAULT_GLOBAL_SHORTCUTS,
-} from './shortcutBindings';

src/config/shortcutBindings.ts

@@ -1,4 +1,4 @@
-import type { ShortcutSlot } from './shortcutTypes';
+import type { ShortcutSlot } from '@/lib/shortcuts/shortcutTypes';
 import {
   SHORTCUT_ACTION_REGISTRY,
   type ShortcutAction,

src/config/shortcutDispatch.ts

@@ -3,7 +3,7 @@ import i18n from '@/lib/i18n';
 import { usePlayerStore } from '../store/playerStore';
 import { showToast } from '../utils/ui/toast';
 import { playByOpaqueId } from '../utils/playback/playByOpaqueId';
-import type { ActionContext, CliContext } from './shortcutTypes';
+import type { ActionContext, CliContext } from '@/lib/shortcuts/shortcutTypes';
 import {
   SHORTCUT_ACTION_REGISTRY,
   type ShortcutAction,

src/config/shortcutTypes.ts

@@ -1,45 +0,0 @@
-// Shared types for the shortcut-action subsystem. The contract overview lives
-// in the barrel, `shortcutActions.ts`.
-
-import type { NavigateOptions } from 'react-router-dom';
-
-export type TranslateLike = (key: string, options?: Record<string, unknown>) => string;
-
-/** One bindable slot (in-app OR global). `defaultBinding` is the out-of-box
- * chord, or `null` for "unbound by default". `hidden` keeps the action out of
- * the Settings shortcut-list UI (still bindable / dispatchable). */
-export type ShortcutSlot = { defaultBinding: string | null; hidden?: boolean };
-
-/** Passed to an action's `run`. `previewPolicy` decides whether an active
- * track-preview is interrupted: 'stop' for explicit UI / in-app keys, 'ignore'
- * for hardware media keys. */
-export type ActionContext = {
-  navigate: (to: string, options?: NavigateOptions) => void;
-  previewPolicy: 'stop' | 'ignore';
-};
-
-/** Passed to `executeCliPlayerCommand` — the raw `cli:player-command` payload
- * plus a navigate fn. */
-export type CliContext = {
-  navigate: (to: string, options?: NavigateOptions) => void;
-  payload: Record<string, unknown>;
-};
-
-/** Registry entry for one shortcut action. `inApp` / `global` /
- * `runInMiniWindow` are the three independent trigger surfaces; `cli` and
- * `run` are surface-independent. See the contract block in `shortcutActions.ts`. */
-export type ShortcutActionMeta = {
-  /** Localized display label for the Settings UI. */
-  getLabel: (t: TranslateLike) => string;
-  /** Present ⇒ bindable to a main-window keyboard chord (id becomes a `KeyAction`). */
-  inApp?: ShortcutSlot;
-  /** Present ⇒ registrable as an OS-level global hotkey (id becomes a `GlobalAction`). */
-  global?: ShortcutSlot;
-  /** Whether the action may run when triggered from the mini-player window. */
-  runInMiniWindow: boolean;
-  /** The handler. */
-  run: (ctx: ActionContext) => void;
-  /** Present ⇒ exposed to `psysonic --player <verb>`. `command` overrides the
-   * CLI verb used for no-arg dispatch (defaults to the action id). */
-  cli?: { verb: string; description: string; command?: string };
-};