feat(client): port character shaders, skin tones, skeleton, and animations (#702, #706)

Port proven shaders (toon, toon_masked, outline) and skin tone textures
from quaternius-aesthetic spike to production client. Import 65-bone
armature and Universal Animation Libraries (UAL1 + UAL2). Set
gltf/embedded_image_handling=3 in project.godot (critical import setting).

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

client/assets/characters/shaders/outline.gdshader

@@ -0,0 +1,14 @@
+shader_type spatial;
+render_mode unshaded, cull_front;
+
+uniform vec4 outline_color : source_color = vec4(0.1, 0.1, 0.15, 1.0);
+uniform float outline_width : hint_range(0.0, 0.1) = 0.03;
+
+void vertex() {
+	// Inverted hull outline: push vertices along normals, render back faces only
+	VERTEX += NORMAL * outline_width;
+}
+
+void fragment() {
+	ALBEDO = outline_color.rgb;
+}

client/assets/characters/shaders/toon.gdshader

@@ -0,0 +1,16 @@
+shader_type spatial;
+render_mode unshaded;
+
+uniform vec4 base_color : source_color = vec4(0.8, 0.6, 0.4, 1.0);
+uniform vec4 shadow_color : source_color = vec4(0.4, 0.3, 0.2, 1.0);
+uniform float shadow_threshold : hint_range(0.0, 1.0) = 0.5;
+
+void fragment() {
+	// Simple toon shading: use normal dot light to pick between base and shadow
+	vec3 light_dir = normalize(vec3(0.3, -1.0, 0.5));
+	float ndl = dot(NORMAL, -light_dir);
+	float toon = step(shadow_threshold, ndl);
+	vec3 color = mix(shadow_color.rgb, base_color.rgb, toon);
+	ALBEDO = color;
+	ALPHA = base_color.a;
+}

client/assets/characters/shaders/toon_masked.gdshader

@@ -0,0 +1,31 @@
+shader_type spatial;
+render_mode unshaded, cull_disabled;
+
+// Original Trellis atlas texture
+uniform sampler2D albedo_tex : source_color;
+// Recolor mask: white = replaceable, black = keep original
+uniform sampler2D recolor_mask : hint_default_black;
+// Runtime tint color set by game code
+uniform vec4 tint_color : source_color = vec4(0.8, 0.8, 0.8, 1.0);
+// Subtle darkening on shadow side (0.0 = no shadow, 1.0 = full black)
+uniform float shadow_strength : hint_range(0.0, 1.0) = 0.15;
+uniform float shadow_threshold : hint_range(0.0, 1.0) = 0.3;
+
+void fragment() {
+	vec4 original = texture(albedo_tex, UV);
+	float mask = texture(recolor_mask, UV).r;
+
+	// Recolor: blend tint with original, preserving luminance in masked regions
+	// This keeps texture detail (shadows, edges, highlights) while changing the hue
+	float luma = dot(original.rgb, vec3(0.299, 0.587, 0.114));
+	vec3 tinted = tint_color.rgb * (luma * 1.5 + 0.2); // scale luma to avoid too-dark
+	vec3 base = mix(original.rgb, tinted, mask);
+
+	// Gentle toon shadow — just a subtle darkening, not a color replacement
+	vec3 light_dir = normalize(vec3(0.3, -1.0, 0.5));
+	float ndl = dot(NORMAL, -light_dir);
+	float toon = smoothstep(shadow_threshold - 0.1, shadow_threshold + 0.1, ndl);
+	vec3 color = base * mix(1.0 - shadow_strength, 1.0, toon);
+
+	ALBEDO = color;
+}

client/project.godot

@@ -152,6 +152,10 @@ quickload={
 ]
 }
 
+[gltf]
+
+embedded_image_handling=3
+
 [rendering]
 
 renderer/rendering_method="gl_compatibility"