feat: localchat, a Go + Templ + HTMX chat app for local Gemma models

Streams replies over SSE from any OpenAI-compatible server (oMLX,
llama.cpp, Ollama, ...). Single binary that can install itself as an
OS service; docker compose bundles llama.cpp + Gemma 4 E2B.

internal/web/static/app.css

@@ -0,0 +1,156 @@
+:root {
+  --bg: #f7f7f5;
+  --surface: #ffffff;
+  --text: #1d1d1f;
+  --muted: #6e6e73;
+  --border: #e3e3e0;
+  --accent: #3b6cf6;
+  --accent-text: #ffffff;
+  --user-bg: #3b6cf6;
+  --user-text: #ffffff;
+  --code-bg: #f0f0ed;
+  --ok: #22a356;
+  --bad: #d64545;
+  --radius: 14px;
+  color-scheme: light dark;
+}
+
+@media (prefers-color-scheme: dark) {
+  :root {
+    --bg: #131315;
+    --surface: #1d1d20;
+    --text: #ececef;
+    --muted: #9a9aa2;
+    --border: #2c2c31;
+    --accent: #6b8fff;
+    --user-bg: #3d5fd9;
+    --code-bg: #26262b;
+  }
+}
+
+* { box-sizing: border-box; }
+
+html, body { height: 100%; margin: 0; }
+
+body {
+  display: grid;
+  grid-template-rows: auto 1fr auto;
+  max-width: 820px;
+  margin: 0 auto;
+  background: var(--bg);
+  color: var(--text);
+  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
+}
+
+header {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  padding: 14px 16px;
+  border-bottom: 1px solid var(--border);
+}
+header h1 { font-size: 1.05rem; margin: 0; flex: 1; }
+header form { margin: 0; }
+
+.health { display: flex; align-items: center; gap: 6px; font-size: .85rem; color: var(--muted); }
+.dot { width: 8px; height: 8px; border-radius: 50%; background: var(--muted); }
+.dot.ok { background: var(--ok); }
+.dot.bad { background: var(--bad); }
+
+#messages {
+  overflow-y: auto;
+  padding: 20px 16px;
+  display: flex;
+  flex-direction: column;
+  gap: 14px;
+}
+
+.empty { margin: auto; text-align: center; color: var(--muted); }
+.empty .big { font-size: 2rem; margin: 0; }
+.empty:not(:only-child) { display: none; }
+
+.msg { display: flex; }
+.msg.user { justify-content: flex-end; }
+
+.bubble {
+  max-width: min(85%, 680px);
+  padding: 10px 14px;
+  border-radius: var(--radius);
+  background: var(--surface);
+  border: 1px solid var(--border);
+  overflow-wrap: anywhere;
+}
+.msg.user .bubble {
+  background: var(--user-bg);
+  color: var(--user-text);
+  border-color: transparent;
+  border-bottom-right-radius: 4px;
+}
+.msg.assistant .bubble { border-bottom-left-radius: 4px; }
+
+.content.plain { white-space: pre-wrap; }
+.markdown > :first-child { margin-top: 0; }
+.markdown > :last-child { margin-bottom: 0; }
+.markdown pre {
+  background: var(--code-bg);
+  padding: 10px 12px;
+  border-radius: 8px;
+  overflow-x: auto;
+  font-size: .9em;
+  tab-size: 4;
+}
+.markdown code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }
+.markdown :not(pre) > code { background: var(--code-bg); padding: 1px 5px; border-radius: 5px; font-size: .9em; }
+.markdown table { border-collapse: collapse; }
+.markdown th, .markdown td { border: 1px solid var(--border); padding: 4px 8px; }
+.markdown a { color: var(--accent); }
+
+.error { color: var(--bad); font-size: .9rem; margin: 6px 0 0; }
+
+/* typing indicator while waiting for the first token */
+.streaming:empty::after {
+  content: "● ● ●";
+  letter-spacing: 2px;
+  color: var(--muted);
+  animation: pulse 1.2s ease-in-out infinite;
+}
+@keyframes pulse { 50% { opacity: .3; } }
+
+#composer {
+  display: flex;
+  gap: 8px;
+  padding: 12px 16px 18px;
+  border-top: 1px solid var(--border);
+}
+#composer textarea {
+  flex: 1;
+  resize: none;
+  max-height: 200px;
+  padding: 10px 12px;
+  border: 1px solid var(--border);
+  border-radius: var(--radius);
+  background: var(--surface);
+  color: var(--text);
+  font: inherit;
+}
+#composer textarea:focus { outline: 2px solid var(--accent); outline-offset: -1px; }
+
+button {
+  padding: 0 18px;
+  border: 0;
+  border-radius: var(--radius);
+  background: var(--accent);
+  color: var(--accent-text);
+  font: inherit;
+  font-weight: 600;
+  cursor: pointer;
+}
+button:disabled { opacity: .5; cursor: progress; }
+button.ghost {
+  padding: 6px 12px;
+  background: transparent;
+  color: var(--muted);
+  border: 1px solid var(--border);
+  font-weight: 500;
+  font-size: .85rem;
+}