Sunset the dedicated cutscene asset loader and the item pool

Cutscenes now load through the generic ASSET_LOADER_TYPE_JSON loader
and parse straight into fixed static buffers via new cutsceneParseDoc/
cutsceneParseItem/cutsceneCountItems helpers (cutscene.c), removing the
bespoke ASSET_LOADER_TYPE_CUTSCENE pipeline entirely. Only one cutscene
(plus one INSERT target) is ever resident, so each resolve locks,
steals the parsed doc, unlocks, and force-reaps immediately - fixing a
stale-cache-reuse bug where revisiting a cutscene name after a
different one could return data from the shared buffer's previous
occupant.

ENTITY_WALK_TO and MAP_AREA_WAIT now store their waypoints/area ids in
fixed-size arrays inline on their own item struct instead of a shared
bump-allocated pool, so pool/poolOffset are gone from every item type's
Load callback. cutscene_t.dataSize (and the CUTSCENE(...) macro's SIZE
parameter) is removed along with it - it sized entries out of that same
now-deleted pool and had no other reader.

NPC #4's battletest cutscene and the main menu's cutscene now resolve
their target by name on interact instead of eagerly at init, so a
resolved-once pointer is never held past the point its backing buffer
can be reused for something else.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

src/dusk/rpg/cutscene/item/audio/cutsceneaudioresume.h

@@ -45,13 +45,9 @@ bool_t cutsceneAudioResumeUpdate(
  *
  * @param itemObj The item's JSON object.
  * @param item Destination item, already zeroed by the caller.
- * @param pool Unused (AUDIO_RESUME needs no pool storage).
- * @param poolOffset Unused (AUDIO_RESUME needs no pool storage).
  * @return Error code indicating success or failure of the parse.
  */
 errorret_t cutsceneAudioResumeLoad(
   yyjson_val *itemObj,
-  cutsceneitem_t *item,
-  uint8_t *pool,
-  size_t *poolOffset
+  cutsceneitem_t *item
 );