perf(content): close prepared asset cutover

docs/architecture/worldbuilder-inventory.md

@@ -35,9 +35,10 @@ acdream streams asynchronously while the WB editor's manager owned its own loadi
 loop. Do not reintroduce worker-side `RegisterCell` calls or shared pending cell
 collections.
 
-`DatCollectionAdapter` bridges our `IDatCollection` to the `IDatReaderWriter`
-interface WB's internals expect (O-D7 fallback; `ObjectMeshManager` has 26
-internal `_dats.*` call sites — above the 20-site inline-swap threshold).
+`DatCollectionAdapter` bridges the sole `DatCollection` to Content's
+`IDatReaderWriter`. Since MP1c, production `ObjectMeshManager` no longer reads
+DAT; the adapter remains the bounded typed-object access seam for runtime
+non-render content plus explicit bake/equivalence tooling.
 
 **MP1a (2026-07-05): CPU mesh-extraction half moved to `AcDream.Content`.**
 The GL-free portion of the former `ObjectMeshManager` — dat read → polygon
@@ -82,14 +83,13 @@ behavior change, no divergence-register row.
   throw (preloads staged before a malformed-dat texture-decode exception
   survive, as they always did). The MP1b bake tool passes its own
   collector.
-- **Stays in `src/AcDream.App/Rendering/Wb/`:** `ObjectMeshManager` (now a
-  thin wrapper owning the staged-queue/worker-pool/Dispose-quiesce lifecycle
-  and all GL upload — constructs one `MeshExtractor` and delegates every
-  former `Prepare*` call site to it), `ObjectRenderData`/`ObjectRenderBatch`
+- **Stays in `src/AcDream.App/Rendering/Wb/`:** `ObjectMeshManager` (the
+  staged-queue/worker-pool/Dispose-quiesce lifecycle and all GL upload;
+  production workers now consume `IPreparedAssetSource`),
+  `ObjectRenderData`/`ObjectRenderBatch`
   (hold a GL `TextureAtlasManager` field), `TextureAtlasManager`,
-  `DatCollectionAdapter` (concrete `DatCollection`-backed implementation of
-  the now-Content-namespaced `IDatReaderWriter`), `GeometryUtils` (used only
-  by App-side raycasting, not by extraction), `AcSurfaceMetadata`/
+  `GeometryUtils` (used only by App-side raycasting, not by extraction),
+  `AcSurfaceMetadata`/
   `AcSurfaceMetadataTable` (not on the extraction path), `Building.cs`
   (explicitly out of scope).
 - `AcDream.Core` is untouched; `AcDream.Content` references `AcDream.Core`
@@ -114,6 +114,23 @@ aliasing and fails on any collision. This is an acdream resource-ownership seam,
 not a second DAT interpreter; `DatCollection` and `MeshExtractor` remain the
 only reader/extractor path.
 
+**MP1c production prepared-asset cutover (2026-07-24).** Production
+world-mesh workers no longer invoke `MeshExtractor` or rebuild Setup, GfxObj,
+EnvCell, Surface, palette, and texture graphs during portals. The validated
+machine-local `acdream.pak` is opened through Content's
+`IPreparedAssetSource`; typed GfxObj and EnvCell requests deserialize immutable
+`ObjectMeshData` while retaining the existing App worker, staging, render-thread
+upload, cache, ownership, and shutdown contracts. The format-1/bake-tool-3
+payload persists exact batch translucency so App does not reconstruct a
+`GfxObjMesh` for metadata. Setup activation uses the package TOC as an explicit
+type-presence index before reading valid Setup records through the bounded DAT
+cache. `DatPreparedAssetSource` and `MeshExtractor` remain explicit
+bake/equivalence/UI-Studio tools, not a production fallback. Portal → HighRes
+→ Language → Cell lookup precedence is encoded directly in
+`DatCollectionAdapter.TryResolvePreferred`. The connected physical and
+installed-DAT gates are recorded in
+`docs/research/2026-07-24-slice-c-prepared-asset-cutover-report.md`.
+
 **Retail VFX hook compatibility seam (2026-07-14).** Chorizite.DatReaderWriter
 2.1.7 models `CreateBlockingParticleHook` as the common hook header only, while
 retail inherits the complete `CreateParticleHook` payload. The narrow readers in