Migrate Vite SPA to Hugo (hugo-coder, dark) with WebGPU background

- Hugo static site at root: config, content (home/about/resume/blog + 5 projects),
  data/resume.yaml, custom layouts (gpu background, resume renderer, projects list),
  dark theme with canvas behind content
- gpu-bg/: extracted WebGPU/WebGL2 spiral engine as a Vite sub-package; slim bootstrap
  drops router/overlay/text renderer; fixed uniforms (scene0/dim0); self-contained engine.js
- archive/: retired Vite SPA preserved (router, overlay, data, engine/text orphaned)
- 3-stage Dockerfile (node -> hugo extended/dart-sass -> nginx), static nginx config
- DEPLOYMENT.md handover + README rewrite; pre-hugo rollback tag

gpu-bg/src/shaders/fullscreen.wgsl

@@ -0,0 +1,108 @@
+struct Uniforms {
+  resolution: vec2<f32>,
+  time: f32,
+  scene: f32,
+  mouse: vec2<f32>,
+  date: vec4<f32>,
+  sampleRate: vec4<f32>,
+  stemMultipliers: array<vec4<f32>, 8>,
+};
+
+@group(0) @binding(0) var<uniform> u: Uniforms;
+
+struct VsOut {
+  @builtin(position) pos: vec4<f32>,
+  @location(0) uv: vec2<f32>,
+};
+
+@vertex
+fn vs(@builtin(vertex_index) i: u32) -> VsOut {
+  let p = array<vec2<f32>, 3>(
+    vec2<f32>(-1.0, -3.0),
+    vec2<f32>(-1.0, 1.0),
+    vec2<f32>(3.0, 1.0),
+  );
+  let clip = p[i];
+  var out: VsOut;
+  out.pos = vec4<f32>(clip, 0.0, 1.0);
+  out.uv = clip;
+  return out;
+}
+
+@fragment
+fn fs(in: VsOut) -> @location(0) vec4<f32> {
+  let res = u.resolution;
+  let fragCoord = (in.uv * vec2<f32>(0.5) + vec2<f32>(0.5)) * res;
+
+  var uv = (fragCoord - 0.5 * res) / res.y;
+
+  let slowTime = u.time * 0.2;
+
+  let bgGrey = vec3<f32>(0.11, 0.11, 0.12);
+  let cardGrey = vec3<f32>(0.30, 0.32, 0.36);
+  let coreWhite = vec3<f32>(0.90, 0.95, 0.90);
+
+  // ---------- palette keyed by scene ----------
+  let scene0 = vec3<f32>(0.20, 0.75, 0.20);   // HERO   – emerald
+  let scene1 = vec3<f32>(0.85, 0.55, 0.20);   // ABOUT  – amber
+  let scene2 = vec3<f32>(0.25, 0.60, 0.95);   // PROJECTS – cobalt
+  let scene3 = vec3<f32>(0.90, 0.35, 0.55);   // CONTACT – rose
+
+  let sFloor = i32(clamp(floor(u.scene), 0.0, 3.0));
+  let sCeil  = i32(clamp(ceil(u.scene), 0.0, 3.0));
+  var c0 = scene0;
+  c0 = select(c0, scene1, sFloor == 1);
+  c0 = select(c0, scene2, sFloor == 2);
+  c0 = select(c0, scene3, sFloor == 3);
+  var c1 = scene0;
+  c1 = select(c1, scene1, sCeil == 1);
+  c1 = select(c1, scene2, sCeil == 2);
+  c1 = select(c1, scene3, sCeil == 3);
+  let tBlend = u.scene - floor(u.scene);
+  let sceneAccent = mix(c0, c1, tBlend * tBlend * (3.0 - 2.0 * tBlend));
+
+  // ---------- mouse-reactive distortion ----------
+  let mousePos = (u.mouse - 0.5 * res) / res.y;
+  let distMouse = length(uv - mousePos);
+  let influence = exp(-distMouse * 7.0);
+  uv += (mousePos - uv) * influence * 0.12;
+
+  let angle = atan2(uv.y, uv.x);
+  let radius = length(uv);
+
+  let baseSpiral = angle + (radius * 8.0) - slowTime;
+  let ripple = sin(radius * 15.0 - (u.time * 0.5)) * 0.08;
+  let distortedSpiral = baseSpiral + ripple;
+
+  let armCount = 2.0;
+  let rChannel = smoothstep(0.05, 0.55, abs(sin((distortedSpiral + 0.04) * armCount)));
+  let gChannel = smoothstep(0.05, 0.55, abs(sin(distortedSpiral * armCount)));
+  let bChannel = smoothstep(0.05, 0.55, abs(sin((distortedSpiral - 0.04) * armCount)));
+  let patternChannels = vec3<f32>(rChannel, gChannel, bChannel);
+
+  let coreNeon = vec3<f32>(0.02 / (patternChannels + 0.025));
+  let spiralColor = mix(cardGrey, sceneAccent, patternChannels.g);
+  let primarySpiral = coreNeon * spiralColor;
+
+  let ringWave = sin(radius * 12.0 - (u.time * 1.5));
+  let sharpRing = smoothstep(0.85, 0.95, ringWave);
+  let ringMask = sharpRing * smoothstep(0.7, 0.1, radius);
+  let secondaryRings = cardGrey * ringMask * 0.4;
+
+  let vignette = smoothstep(0.95, 0.4, radius);
+
+  var finalColor = bgGrey + secondaryRings;
+  finalColor = mix(finalColor, primarySpiral, 0.85);
+
+  let centerLight = 0.015 / (radius + 0.02);
+  finalColor += centerLight * coreWhite;
+
+  // soft cursor glow
+  finalColor += exp(-distMouse * 4.0) * 0.03 * sceneAccent;
+
+  // ---------- dim when not on the home page (u.date.x controls it) ----------
+  let dim = u.date.x;
+  finalColor = mix(finalColor, vec3<f32>(0.0), dim);
+
+  return vec4<f32>(finalColor * vignette, 1.0);
+}