Add formal enemies, remaining formal partners and synthesized UI SFX

- UI SFX v3: procedurally synthesized one-shots (Tools/synth_ui_sfx.py) wired to
  buttons, rewards, errors and red dots via UiSfx, gated by the SFX setting.
- Five formal enemies (Hornlet, Dashlet, Shellhorn, HornCaptain, GreatHorn):
  Hunyuan 50k -> 2000-tri XPbr, DGXA TokenRig, Idle/Walk/Attack, nested per type
  in PrototypeArena; PrototypeBattle.Enemy gains presentation-only Moving/Strikes.
- Formal partners for all ten pets in the arena and portraits, including new
  VineSprite, ThunderLeopard and TideWhale.
- Pipeline fixes: reject local TokenRig fallback, drop loose mesh islands,
  configurable Unity run_script timeout, companion static stage.
- Also includes concurrent work from another tool in this working tree
  (FlameLion, enemy combat FX, challenge mode, home explorer, server updates).
- Resources registered in Doc/ResDesc_*.md; verified on isolated :18081.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Tools/model_tools/bl_transfer_skin.py

@@ -157,6 +157,33 @@ def main():
     # recipe-defined geodesic masks can bind that appendage to an existing
     # stable bone without changing geometry, UVs or the animation skeleton.
     override_reports=[]
+    # Explicit source-space regions can bind a rigid carapace without altering
+    # geometry/UVs. The recipe must be fitted to this character's inspected mesh.
+    if args.weight_overrides:
+        rules=json.loads(args.weight_overrides.read_text(encoding='utf-8-sig')).get('skinRegions',[])
+        extent=max(p.y for p in original_points)-min(p.y for p in original_points)
+        points=[p/extent for p in original_points]
+        for rule in rules:
+            if rule['bone'] not in arm.data.bones:raise ValueError('Region bone missing')
+            lo,hi=rule['min'],rule['max'];feather=rule.get('feather',0)
+            if feather<0 or any(lo[c]>=hi[c] for c in range(3)):raise ValueError('Invalid rigid region')
+            target=low.vertex_groups[rule['bone']];affected=[];full=[]
+            for i,p in enumerate(points):
+                distance=max(max(lo[c]-p[c],0,p[c]-hi[c]) for c in range(3))
+                if distance>feather:continue
+                weight=1 if distance==0 else 1-distance/feather
+                weight=weight*weight*(3-2*weight)
+                previous={g.group:g.weight for g in low.data.vertices[i].groups}
+                for group,value in previous.items():low.vertex_groups[group].add([i],value*(1-weight),'REPLACE')
+                target.add([i],previous.get(target.index,0)*(1-weight)+weight,'REPLACE')
+                affected.append(i)
+                if distance==0:full.append(i)
+            if not full:raise ValueError('Rigid region selected no vertices')
+            override_reports.append(dict(kind='source_space_region',bone=rule['bone'],affected=len(affected),full_weight_vertices=len(full),
+                normalized_min=[min(points[i][c] for i in affected) for c in range(3)],
+                normalized_max=[max(points[i][c] for i in affected) for c in range(3)]))
+
+    # More precise geodesic appendage overrides run after broad spatial regions.
     if args.weight_overrides:
         overrides=json.loads(args.weight_overrides.read_text(encoding='utf-8-sig')).get('skinOverrides',[])
         extent=max(p.y for p in original_points)-min(p.y for p in original_points)