feat: stack quick-capture box on chat page (no LLM)

Slim numeric input below the message box; posts to /session/stack and
drops a confirmation line into the Live Log without a chat turn.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01G796GsLCvJQKVN7hwV2cDx

lyra/web/static/index.html

@@ -124,6 +124,12 @@
       <button id="sendBtn" aria-label="Send" title="Send (or ⌘/Ctrl+Enter)">↑</button>
     </div>
 
+    <!-- Stack quick-capture (no LLM): type a number -> logs current stack -->
+    <div id="stackQuick">
+      <input id="stackQuickInput" type="number" inputmode="decimal" placeholder="Stack $" aria-label="Log current stack">
+      <button id="stackQuickBtn" type="button" title="Log stack (no chat)">Log</button>
+    </div>
+
     <!-- Bottom tab bar (mobile only; hides while the keyboard is open) -->
     <nav id="tabbar" aria-label="Primary navigation">
       <a class="tab active" href="/" aria-current="page"><span class="ti">💬</span><span class="tl">Chat</span></a>
@@ -209,6 +215,52 @@
     const API_URL = `${RELAY_BASE}/v1/chat/completions`;
     const STREAM_URL = `${RELAY_BASE}/v1/chat/stream`;
 
+    // Stack quick-capture (no LLM): type a number -> POST /session/stack.
+    function stackQuickLog() {
+      const el = document.getElementById("stackQuickInput");
+      if (!el) return;
+      const raw = (el.value || "").replace(/[^0-9.]/g, "");
+      if (!raw) return;
+      const amount = Number(raw);
+      const content = document.getElementById("thinkingContent");
+      const empty = document.getElementById("thinkingEmpty");
+      fetch("/session/stack", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ amount })
+      }).then(r => r.json()).then(data => {
+        if (empty && empty.parentNode) empty.parentNode.removeChild(empty);
+        const line = document.createElement("div");
+        const t = new Date().toLocaleTimeString();
+        if (!data.ok) {
+          line.className = "log-line log-error";
+          line.textContent = "⚠ " + (data.error || "stack not logged");
+        } else {
+          line.className = "log-line log-info";
+          const net = (data.stack && data.stack.net != null)
+            ? " (net " + (data.stack.net >= 0 ? "+" : "") + data.stack.net + ")" : "";
+          line.textContent = t + "  💰 $" + amount + " logged" + net;
+          el.value = "";
+        }
+        if (content) { content.appendChild(line); content.scrollTop = content.scrollHeight; }
+      }).catch(e => {
+        if (content) {
+          const line = document.createElement("div");
+          line.className = "log-line log-error";
+          line.textContent = "⚠ stack log failed: " + e.message;
+          content.appendChild(line);
+        }
+      });
+    }
+    (function wireStackQuick() {
+      const btn = document.getElementById("stackQuickBtn");
+      const inp = document.getElementById("stackQuickInput");
+      if (btn) btn.addEventListener("click", stackQuickLog);
+      if (inp) inp.addEventListener("keydown", function (e) {
+        if (e.key === "Enter") { e.preventDefault(); stackQuickLog(); }
+      });
+    })();
+
 	function generateSessionId() {
       return "sess-" + Math.random().toString(36).substring(2, 10);
     }

lyra/web/static/style.css

@@ -1231,3 +1231,31 @@ select:hover {
     scroll-behavior: auto !important;
   }
 }
+
+/* Stack quick-capture (2nd input box on the chat page) — logs without the LLM. */
+#stackQuick {
+  display: flex;
+  gap: 8px;
+  align-items: center;
+  padding: 6px 12px;
+  border-top: 1px solid var(--border);
+  background: var(--bg-panel);
+}
+#stackQuick input {
+  flex: 1;
+  min-width: 0;
+  padding: 8px 10px;
+  background: var(--bg-elev);
+  color: inherit;
+  border: 1px solid var(--border);
+  border-radius: 8px;
+}
+#stackQuick button {
+  padding: 8px 14px;
+  background: var(--accent);
+  color: #000;
+  border: none;
+  border-radius: 8px;
+  font-weight: 600;
+  cursor: pointer;
+}