Consolidate documentation into architecture and merged guides

docs/blender-assets.md

@@ -39,7 +39,7 @@ captures in `docs/screenshots/`.
 
 Blender MCP can be used for interactive head/face/hand part exploration, but it
 is not required. The headless commands below remain the build and audit path;
-see [`blender-mcp.md`](blender-mcp.md) for installation, connection and safety.
+see [`asset-tooling.md#optional-interactive-blender-mcp`](asset-tooling.md#optional-interactive-blender-mcp) for installation, connection and safety.
 
 ## Running it
 
@@ -91,35 +91,10 @@ render about 2.5 min.
 
 ## Characters
 
-All eight use the `npc_base` contract, so each one can replace
-`npc_base.glb` without code changes:
-
-- mesh node `npc_base` under an armature that imports as `Skeleton3D`
-- bones `Head`, `HipL/R`, `KneeL/R`, `ShoulderL/R`, `ElbowL/R`, `HandL/R`
-  (plus `Hips`, `Spine`, `Neck`) at the **same rest positions as `npc_base`**.
-  `test_character_joints_line_up_with_npc_base` checks this within 1 cm, so the
-  animation proxies in `_build_skinned_body()` stay valid.
-- material slots `skin`, `cloth`, `pants`, `accessory`, `hair` carry the same
-  neutral `assets/textures/npc/<slot>_{albedo,normal}.png` maps at 256², so
-  `Materials.npc_slot()` tints them the same way it tints `npc_base`. Cloth and
-  pants repeat the weave 4× (`NPC_FABRIC_UV_SCALE`) and intentionally skip the
-  per-character baked AO; skin, hair and fixed gear keep it.
-- budget ≤ **16,000 triangles and ≤ 16,000 glTF vertices** per character (vertex count after
-  seam splits; `CHAR_MAX_TRIS`/`CHAR_MAX_VERTS` in `tools/blender_assets.py`). The 13 core bones
-  remain required; optional extra bones are allowed as long as the core rest positions and
-  `NpcAvatar` animation proxies are unchanged. The frozen low-poly `npc_base` fallback keeps its
-  compact geometry but is no longer capped at 6,000/4,000. The current range is 5,038–6,030
-  triangles and 4,756–5,902 vertices, leaving substantial head/hand headroom.
-
-Construction: the torso and limbs are one continuous Skin-modifier mesh,
-subdivided twice, decimated to 26 % with X symmetry, and cut at the waist, cuffs,
-sleeves and neck so the material borders are clean edge loops. The head is a
-separate part carrying the face detail: brow ridge, sclera/iris/upper-lid per eye,
-cheekbones, a nose with a bridge and tip, ears with lobes, and upper and lower
-lips. Hands have four fingers plus a thumb; sleeves end in a cuff ring.
-Hair, shoes and clothing layers are separate parts. Weights come from distance to
-the bone segments, limited by body region. Parts that should stay rigid (head,
-hands, shoes) get a single bone.
+All library variants share the [character and gear asset contract](architecture.md#character-and-gear-asset-contract):
+`npc_base` mesh node, required 13 core bones (optional extras allowed), five
+tint slots, +Z visual front, 16,000/16,000 character budget and the same 256²
+slot-map/AO rules. Role selection and look notes:
 
 | Character | `layer_for()` / look | Suggested roles | Preview gear |
 | --- | --- | --- | --- |
@@ -146,22 +121,8 @@ the role's `TYPE_COLORS`.
 
 ## Gear attach points
 
-Gear is authored in attach-point space, so the origin of each GLB is its
-attach point:
-
-| Attach | Godot parent / position | Gear |
-| --- | --- | --- |
-| `head` | `Rig/Head` marker (0, 1.62, 0) | cap, hood, sunglasses, firefighter_helmet |
-| `back` | `Rig` at (0, 1.10, 0), spine centre; items sit behind the body (Blender +Y = Godot −Z) | backpack, shoulder_bag, scba_tank |
-| `chest` | `Rig` at (0, 1.30, 0), sternum | lanyard |
-| `hand` | Hand proxy (±0.27, 0.78, 0.02); grip 5 cm below the origin | phone, cup, clipboard, umbrella, camera, protest_sign, flashlight, wand, radio |
-
-The character previews in `sheet_npc.jpg` are built by importing the gear at
-exactly these points, which gives a quick visual check of the convention.
-`NpcAvatar.GEAR_OFFSETS` applies two final-context nudges after attachment:
-the lanyard moves 4 cm forward so its badge clears the jacket, and the
-firefighter helmet moves 3 cm up so its brim sits above the eyes. The
-`fit` report remains an asset-space measurement of the untouched GLBs.
+Gear is authored in attach-point space; the exact contract and runtime fit offsets are in
+[`architecture.md#character-and-gear-asset-contract`](architecture.md#character-and-gear-asset-contract).
 
 ## Props