Stage the Blender character/gear/prop library

Commit the finished generator output from the parallel Blender pass:
8 skinned NPC variants, 18 gear pieces, and 20 props under
assets/models/blender/, editable sources (gdignored), manifest, review sheets,
and the integration notes in docs/blender-assets.md.

- audit: all 46 assets clean (characters 3,788-4,640 tris, under 6000/4000)
- tests: Python manifest/audit contract and Godot import/bone/slot/ground checks
- docs: README library section, architecture/plan references, TODO Phase 3.5
  status, MEMORY integration rules
- .gitignore: per-asset preview PNGs, extracted GLB textures, blend1 backups

Nothing in the game loads the library yet; integration follows." && git log --oneline -1

docs/architecture.md

@@ -80,6 +80,7 @@ The player interacts with NPCs, venue entrances, access artifacts, equipment, st
 - `WorldBuilder` assembles the procedural venue and instantiates the generated prop models from `assets/models/generated/` with a procedural fallback.
 - `tools/model_pipeline.py` builds and audits the street-prop `.glb` models and packs their colour atlases.
 - `tools/npc_pipeline.py` builds and audits the skinned NPC base model (`assets/models/generated/npc_base.glb`) and its per-slot material maps, with an optional AI fabric override (ADR-0013).
+- `tools/blender_assets.py` builds, renders and audits the staged Blender asset library (`assets/models/blender/{npc,npc_gear,props}/` + `manifest.json`): NPC character variants that are drop-in for `npc_base`, attach-point gear, and street/venue props. Not loaded at runtime yet (see `docs/blender-assets.md`).
 - `tools/asset_pipeline.py` generates and audits role-aware textures; `tools/screen_designs.py` generates screen references and judges captures.
 
 Confirmed game assets live in `assets/textures/ai/game_ready/` (audited surface, UI, and card textures), `assets/models/generated/` (prop and NPC `.glb` models plus their texture atlases), and `assets/textures/npc/` (NPC material maps and `palette.json`). Development-only outputs — AI concept sheets, Blender sources, raw AI fabrics — are gitignored and regenerated by the tools.