perf(render): consume prepared mesh package at runtime

docs/plans/2026-07-24-modern-runtime-slice-c-prepared-assets.md

@@ -2,7 +2,14 @@
 
 **Date:** 2026-07-24
 
-**Status:** active
+**Status:** active — C1 and C2 landed; C3 next
+
+**Checkpoint ledger:**
+
+- C1 typed prepared-source boundary — `c42f93b3`
+- C2 production renderer injection — implementation complete and gated
+- C3 activation probes and lookup precedence — next
+- C4 connected equivalence and performance closeout — pending
 
 **Parent:** [`2026-07-24-modern-runtime-architecture.md`](2026-07-24-modern-runtime-architecture.md),
 Slice C / MP1c
@@ -198,6 +205,9 @@ Implement:
 - `WorldRenderComposition` and `WbMeshAdapter` injection;
 - `ObjectMeshManager` worker reads through `IPreparedAssetSource`;
 - source Cell DID propagation for EnvCell aliases;
+- exact `TranslucencyKind` persisted per prepared texture batch, removing the
+  render-thread `GfxObjMesh.Build` metadata reconstruction (bake-tool identity
+  advances to version 3; the pak container remains format version 1);
 - exact terminal-failure and cancellation semantics;
 - current CPU cache, staging, upload, retry, ownership, and shutdown behavior
   retained;