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/tests/test_character_visual_sprint28.gd

@@ -15,7 +15,7 @@
 ##   5. Facing rotation (set_facing / rotation change)
 ##   6. Edge cases: empty hair_id, no clothing, no accessories
 ##
-## Spec: D-159 (body types), D-160 (15+2+2 segments), D-161 (head on Head bone),
+## Spec: D-159 (body types), D-160 (17 bone-group regions), D-161 (head on Head bone),
 ##       D-162 (clothing pre-baked per body type), D-164 (fork skeleton)
 ## Ticket: #704
 class_name TestCharacterVisualSprint28
@@ -158,10 +158,11 @@ func test_reload_descriptor_clears_previous_nodes() -> void:
 	if count_after_first == 0:
 		push_warning("TestCharacterVisualSprint28: node count 0 — assets may not be present yet")
 		return
-	# Second load must not double the children (would indicate no cleanup)
-	assert_bool(count_after_second <= count_after_first * 2).override_failure_message(
-		"load_descriptor must clear previous node tree before building new one — children doubled, suggesting stale nodes were kept"
-	).is_true()
+	# Second load must produce exactly the same child count — no more, no less.
+	# _clear() frees and rebuilds; any deviation indicates stale nodes accumulating.
+	assert_int(count_after_second).override_failure_message(
+		"load_descriptor must produce identical child count on reload — stale nodes detected if higher, missing cleanup if lower"
+	).is_equal(count_after_first)
 
 
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