refactor(glsl): rename uniforms as iXxx

shaders/frag7.glsl

@@ -8,11 +8,11 @@ in vec2 vUV;
 out vec4 fragColor;
 
 void main() {
-    float mix_value = magic(src3_1[1].xy, vec3(1, 0, 0), seed7);
-    bool mix_type = magic_trigger(vec3(src3_1[0].x, 0, 0), seed7 + 10);
+    float mix_value = magic(iMidi3_1[1].xy, vec3(1, 0, 0), iSeed7);
+    bool mix_type = magic_trigger(vec3(iMidi3_1[0].x, 0, 0), iSeed7 + 10);
 
-    vec4 color_a = texture(tex7, vUV);
-    vec4 color_b = texture(tex8, vUV);
+    vec4 color_a = texture(iTex7, vUV);
+    vec4 color_b = texture(iTex8, vUV);
 
     float k = mean(color_a);