Remove unused files: old UI, build scripts, fonts, test files

Remove old widget-based Python UI (replaced by QML), unused build
scripts, NL/variable/webfont variants, old shaders, PNG icons
(replaced by SVGs), and standalone test files. Add build.bat and
build.spec for the bootstrapper build system.

src/ui/qml/glass.frag

@@ -1,50 +0,0 @@
-#version 440
-
-layout(location = 0) in vec2 qt_TexCoord0;
-layout(location = 0) out vec4 fragColor;
-
-layout(std140, binding = 0) uniform buf {
-    mat4 qt_Matrix;
-    float qt_Opacity;
-    float time;
-    float aberration; // 0.0 to 1.0, controlled by Audio Amplitude
-};
-
-float rand(vec2 co) {
-    return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453);
-}
-
-void main() {
-    // 1. Calculate Distortion Offset based on Amplitude (aberration)
-    // We warp the UVs slightly away from center
-    vec2 uv = qt_TexCoord0;
-    vec2 dist = uv - 0.5;
-    
-    // 2. Chromatic Aberration
-    // Red Channel shifts OUT
-    // Blue Channel shifts IN
-    float strength = aberration * 0.02; // Max shift 2% of texture size
-    
-    vec2 rUV = uv + (dist * strength);
-    vec2 bUV = uv - (dist * strength);
-    
-    // Sample texture? We don't have a texture input (source is empty Item), we are generating visuals.
-    // Wait, ShaderEffect usually works on sourceItem. 
-    // Here we are generating NOISE on top of a gradient.
-    // So we apply Aberration to the NOISE function? 
-    // Or do we want to aberrate the pixels UNDERNEATH?
-    // ShaderEffect with no source property renders purely procedural content.
-    
-    // Let's create layered procedural noise with channel offsets
-    float nR = rand(rUV + vec2(time * 0.01, 0.0));
-    float nG = rand(uv  + vec2(time * 0.01, 0.0)); // Green is anchor
-    float nB = rand(bUV + vec2(time * 0.01, 0.0));
-    
-    // Also modulate alpha by aberration - higher volume = more intense grain?
-    // Or maybe just pure glitch.
-    
-    vec4 grainColor = vec4(nR, nG, nB, 1.0);
-    
-    // Mix it with opacity
-    fragColor = grainColor * qt_Opacity;
-}

src/ui/qml/noise.frag

@@ -1,25 +0,0 @@
-#version 440
-
-layout(location = 0) in vec2 qt_TexCoord0;
-layout(location = 0) out vec4 fragColor;
-
-layout(std140, binding = 0) uniform buf {
-    mat4 qt_Matrix;
-    float qt_Opacity;
-    float time;
-};
-
-// High-quality pseudo-random function
-float rand(vec2 co) {
-    return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453);
-}
-
-void main() {
-    // Dynamic Noise based on Time
-    // We add 'time' to the coordinate to animate the grain
-    float noise = rand(qt_TexCoord0 + vec2(time * 0.01, time * 0.02));
-    
-    // Output grayscale noise with alpha modulation
-    // We want white noise, applied with qt_Opacity
-    fragColor = vec4(noise, noise, noise, 1.0) * qt_Opacity;
-}