Raise the NPC character budget to 24k and refine the prototype neck

MEMORY.md

@@ -114,11 +114,21 @@ canonical implemented-features list in `docs/development-status.md`.
   `docs/asset-tooling.md#optional-interactive-blender-mcp`. The headless flatpak scripts remain authoritative; MCP is
   never a build/CI/test/runtime dependency, and anything MCP touched must pass the
   CLI audit/fit gates.
-- **Character mesh cap (2026-11-04):** all characters use 16,000 tris / 16,000 glTF vertices
+- **Character mesh cap (2026-11-05):** all characters use 24,000 tris / 24,000 glTF vertices
   (`CHAR_MAX_TRIS`/`CHAR_MAX_VERTS` in `tools/blender_assets.py`; `npc_pipeline.MAX_TRIANGLES`/
   `MAX_VERTICES`). The required 13 core bones stay, optional extra bones are allowed, and the
-  low-poly `npc_base` fallback remains the shipped fallback. Measure the 24-NPC/Web budget after
+  low-poly `npc_base` fallback remains the shipped fallback. The raise funds the MPFB body and a
+  seamless neck/shoulder junction. Measure the 24-NPC/Web budget after
   any geometry change; never silently lower the cap without a new decision.
+- **MPFB prototype neck (2026-11-05):** a boolean cylinder (r 0.102) cuts the body neck bore; a
+  smooth lathe covers it. The accepted head keeps a wide flat cut brim at 1.53, so the prototype
+  trims the head at 1.55 (discarding only the neck stub) and matches the lathe to the smaller
+  elliptical opening. This removes the square collar, dark notches and wide brim. Remaining: a
+  thin jaw crease and a hard shirt-shoulder point in three-quarter view. Do not re-add a torus,
+  flat disk, collar shell or destructive neck smoothing; those were rejected.
+- **MPFB prototype count (2026-11-05):** 19,747 tris / 11,475 glTF verts / 1.810 m / 14 bones /
+  10 materials; `inspect` clean. Body-only head/neck surgery lives in
+  `tmp/npc-research/build_mpfb_npc.py` (backups in `/tmp/build_mpfb_npc_94.py`).
 - **Engine baseline:** Godot 4.7.2 stable (official editor `~/.local/bin/godot`). The system's
   `godot-runner` cannot load arbitrary project paths (compiled without path overrides); use the
   official editor binary.