Integrate the Blender character, gear and prop library

NpcAvatar
- select one of 8 library character variants by role/seed (with npc_base and the
  procedural rig as fallbacks), keep Rig/Head and the existing bone animation
- tint only skin/cloth/pants/accessory/hair; fixed detail materials keep their
  colour, npc_vest keeps its hi-vis vest, firefighter/guard use dark uniform tints
- attach caps, hoods, helmets, backpacks, SCBA tanks, lanyards and hand items at
  the documented head/back/chest/hand points (primitive fallbacks retained)

WorldBuilder
- prefer assets/models/blender/props/ for the six replacements and the new
  street dressing (street lamp/tree, palms, planters, A-frame, cone, barrier,
  stanchion, podium, handrail, wall lantern, double door, marquee, sedan)
- fit the same colliders/navigation obstacles and keep the placement validator;
  collect library emissives (bulbs, marquee face, wall lanterns, door LED, sedan
  lights) for set_night_mode()
- add a library triangle counter + 60k budget check (current ~27,986); toggle
  prop gallery to the library models; fix the marquee label placement

Tests/smoke
- character selection/gear attach/fixed-material tint tests; library prop load,
  emissive and triangle-budget tests; smoke_props routes a guest around a
  stanchion in open sidewalk (the old bench route is now crowded by trees)
- headless 222/222, Python 68/68, all smokes pass, compare 11 good / 0 bad

Docs: TODO Phase 3.5 moved to DONE, README/architecture/blender-assets/plan
describe the integrated runtime, MEMORY records the integration rules.

docs/plan-graphics-v0.6.md

@@ -167,8 +167,10 @@ Outputs land under `assets/textures/ai/game_ready/` (or a new
 ### Phase 3.5 — Blender asset library (characters, gear, props)
 
 The library generator is `tools/blender_assets.py` (flatpak Blender, headless).
-It stages outputs for integration; nothing is wired into the game until the
-audit and manifest are clean. Integration notes: [`blender-assets.md`](blender-assets.md).
+**Status: integrated** — `NpcAvatar` selects characters/gear and `WorldBuilder`
+loads the replacement/new props plus phase-driven emissives; the procedural rig
+and primitive props remain fallbacks. Integration notes:
+[`blender-assets.md`](blender-assets.md).
 
 **Outputs and contract**