Finish JerryScript Entity/Scene wiring; remove JSON serialize/deserialize

Register Entity, the generic Component wrapper, and Scene as JerryScript
classes (modulelist.c ties them together, plus their .d.ts stubs), so
scenes/entities can be built from script going forward instead of the
JSON scene format.

With scripting now the intended authoring path, drop the JSON
serialize/deserialize machinery entirely: componentdefinition_t's
serialize/deserialize callbacks, every component's *Serialize/
*Deserialize function, entitySerialize/entityDeserialize,
sceneSerialize/sceneDeserialize, and the "prefabs/<name>.json"/
"scenes/<name>.json" asset fallback in entityPrefabResolveAndApply/
scenePrefabResolveAndApply (C-coded prefabs only now). physicsshape.c
and its test are removed outright since they only existed for this.
game.c's test scene now comes from the existing overworldSceneCreate()
C builder instead of loading the now-deleted assets/scenes/test.json.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

CLAUDE.md

@@ -188,21 +188,85 @@ simply left undefined — the core guards calls with `#ifdef`.
 ## Adding a new entity component
 1. Create `src/dusk/entity/component/<category>/entityMyComp.h/.c` with
    struct `entityMyComp_t`, `entityMyCompInit()`, and optionally
-   `entityMyCompDispose()`.
-2. Add the include to `src/dusk/entity/componentlist.h` header block.
-3. Add a row to `src/dusk/entity/componentlist.h`:
+   `entityMyCompDispose()`, `entityMyCompRender()`.
+2. Add the include to `src/dusk/entity/componentlist.h` header block
+   (or `src/duskrpg/entity/gamecomponentlist.h` for a game-specific
+   component, appended after the engine's inbuilt ones).
+3. Add a row:
    ```c
    X(MYCOMP, entityMyComp_t, myComp, entityMyCompInit, NULL, NULL)
    ```
-   This auto-generates the enum, union field, and definition entry.
+   Params are `(enumName, type, field, init, dispose, render)` — pass
+   `NULL` for any callback the component doesn't need. This
+   auto-generates the enum, union field, and definition entry.
 4. If JS-facing, create the script module and `.d.ts` (see below).
 
+Entities/components/scenes have no JSON serialize/deserialize path —
+that was removed in favor of building scenes from C-coded prefabs
+(below) or from JerryScript (`Entity`/`Component`/`Scene`, see
+"Adding a new script (JS) module").
+
+---
+
+## Adding a new entity/scene prefab
+Entity prefabs (`src/dusk/entity/entityprefab.h`) and scene prefabs
+(`src/dusk/scene/sceneprefab.h`) follow the same pattern:
+1. Write an apply function: `errorret_t entityPrefabXxxApply(mgr,
+   entityId)` (or `errorret_t scenePrefabXxxApply(sceneId)`), building
+   up the entity/scene with the normal component/entity APIs.
+2. Add an entry to the sentinel-terminated `ENTITY_PREFABS[]` (in
+   `src/dusk/entity/entityprefablist.h`, or a game-specific list it
+   includes) or `SCENE_PREFABS[]`:
+   ```c
+   { .name = "MY_PREFAB", .extends = "", .apply = entityPrefabXxxApply }
+   ```
+   `extends` names another prefab to apply first (recurses through
+   `entityPrefabResolveAndApply`/`scenePrefabResolveAndApply`), or `""`
+   for none. Do not add an enum or count field — the array is iterated
+   until `.name[0] == '\0'`.
+3. `entityPrefabResolveAndApply`/`scenePrefabResolveAndApply` only
+   resolve names against the C-coded registry above — there is no JSON
+   asset fallback. Throws if no prefab with that name is registered.
+
+---
+
+## Adding a new cutscene item type
+1. Create `src/duskrpg/cutscene/item/<category>/cutsceneMyItem.h/.c`
+   with a data struct (e.g. `cutscenemyitem_t`) and
+   `cutsceneMyItemStart(item, data)` / `cutsceneMyItemUpdate(item,
+   data)` (the latter returns `true` once the item has completed). Add
+   a matching `cutscenemyitemdata_t` runtime-data struct only if the
+   item needs per-run state across ticks (most don't).
+2. Add `CUTSCENE_ITEM_TYPE_MY_ITEM` to the enum and a union member to
+   `cutsceneitem_t` (and `cutsceneitemdata_t` if it has runtime data) in
+   `src/duskrpg/cutscene/item/cutsceneitem.h`.
+3. Register the `{ start, update }` pair in `CUTSCENE_ITEM_CALLBACKS[]`
+   in `cutsceneitem.c`.
+4. Add an authoring macro to `src/duskrpg/cutscene/cutscene.h`:
+   ```c
+   #define CUTSCENE_MY_ITEM(ARGS...) \
+     { .type = CUTSCENE_ITEM_TYPE_MY_ITEM, .myItem = { ARGS } }
+   ```
+   used inside a `CUTSCENE(NAME, SIZE, PAUSE_TYPE, ...)` block.
+
 ---
 
 ## Adding a new script (JS) module
+Dusk embeds JerryScript (`src/dusk/script/`, fetched via
+`cmake/modules/Findjerryscript.cmake`). Today only `Entity`, the
+generic `Component` wrapper, and `Scene` are registered (see
+`src/dusk/script/module/modulelist.c`) — no per-component-type typed
+wrappers exist yet (e.g. no `.position` on a `POSITION` component);
+`entity.add(TYPE)`/`entity.getComponent(TYPE)` always return the
+generic `Component`.
+
 1. Create `src/dusk/script/module/<category>/moduleMyMod.h/.c`.
    - Declare `extern scriptproto_t MODULE_MYMOD_PROTO;` in the header.
-   - Use `moduleBaseFunction(name)` to define JS-callable functions.
+   - Use `moduleBaseFunction(name)` to define JS-callable functions —
+     these are the one exception to "no `static` in `.c` files": the
+     macro itself expands to a `static jerry_value_t name(...)`
+     JerryScript external-handler trampoline, never called by name
+     from other C files, so it isn't declared in the `.h`.
    - Register props/funcs in `moduleMyModInit()` with
      `scriptProtoDefineProp` / `scriptProtoDefineFunc` /
      `scriptProtoDefineStaticFunc`.
@@ -210,9 +274,12 @@ simply left undefined — the core guards calls with `#ifdef`.
    `src/dusk/script/module/modulelist.c` and call
    `moduleMyModInit()` in `moduleListInit()` (and `Dispose` in
    `moduleListDispose()`).
-3. For component modules also register in
-   `src/dusk/script/module/entity/component/modulecomponentlist.c`
-   so `entity.add()` returns the typed wrapper.
+3. For a component module that adds a *typed* wrapper for a specific
+   component type, create
+   `src/dusk/script/module/entity/component/modulecomponentlist.c` (it
+   doesn't exist yet — the first such module creates it) so
+   `entity.add()` can return the typed wrapper instead of the generic
+   `Component`.
 4. Create `types/<category>/mymod.d.ts` and add a
    `/// <reference path="..." />` line to `types/index.d.ts`.