chore: cleanup TypeScript, update docs, scripts, Dockerfile

- Delete all frontend TypeScript source (src/, index.html, package.json, etc.)
- Move static assets to frontend/static/ (style.css, manifest.json)
- Update scripts/build and scripts/test (no npm steps)
- Update Dockerfile (no frontend build step)
- Update README.md and AGENTS.md for Hyperbole stack

frontend/static/manifest.json

@@ -0,0 +1,13 @@
+{
+  "name": "Sis",
+  "short_name": "Sis",
+  "description": "Shared household chore tracker",
+  "start_url": "/",
+  "display": "standalone",
+  "theme_color": "#fff9e6",
+  "background_color": "#fff9e6",
+  "icons": [
+    { "src": "/icon-192.png", "sizes": "192x192", "type": "image/png" },
+    { "src": "/icon-512.png", "sizes": "512x512", "type": "image/png" }
+  ]
+}

frontend/static/style.css

@@ -0,0 +1,58 @@
+/* Sis custom styles — layered on top of Neo Brutalism */
+
+:root {
+  --nb-red: #e74c3c;
+  --nb-yellow: #f1c40f;
+  --nb-green: #2ecc71;
+  --nb-orange: #e67e22;
+}
+
+body {
+  min-height: 100vh;
+  background: #fff9e6;
+  background-image: radial-gradient(circle, rgba(0,0,0,0.03) 1px, transparent 1px);
+  background-size: 20px 20px;
+  margin: 0;
+  padding: 0;
+}
+
+.nb-navbar {
+  background: #fff;
+  border-bottom: 3px solid #000;
+  padding: 0.75rem 1.5rem;
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  box-shadow: 4px 4px 0 #000;
+  margin-bottom: 2rem;
+}
+
+.nb-navbar-start, .nb-navbar-end {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+}
+
+.nb-list-item {
+  border-bottom: 1px solid rgba(0,0,0,0.1);
+}
+.nb-list-item:last-child {
+  border-bottom: none;
+}
+
+@keyframes fadeIn {
+  from { opacity: 0; }
+  to { opacity: 1; }
+}
+
+@media (max-width: 768px) {
+  .nb-navbar {
+    flex-direction: column;
+    gap: 0.5rem;
+    padding: 0.5rem;
+  }
+  .nb-navbar-end {
+    flex-wrap: wrap;
+    justify-content: center;
+  }
+}