fix(client): address PR #95 review — 8 items

SLOT_TO_BONE expanded to 12 slots (earring_l/r, necklace, wrist_l/r).
_clear() outline teardown ordering fixed. toon_masked.gdshader: removed
cull_disabled, added ALPHA output. _attach_to_bone() returns node instead
of bool. skin_tone clamped in from_dict(). D-160 segment count 15→17.
Blender scripts: docstrings + __main__ guards. Reload test tightened.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

client/assets/characters/shaders/toon_masked.gdshader

@@ -1,5 +1,5 @@
 shader_type spatial;
-render_mode unshaded, cull_disabled;
+render_mode unshaded;
 
 // Original Trellis atlas texture
 uniform sampler2D albedo_tex : source_color;
@@ -28,4 +28,5 @@ void fragment() {
 	vec3 color = base * mix(1.0 - shadow_strength, 1.0, toon);
 
 	ALBEDO = color;
+	ALPHA = original.a * tint_color.a;
 }