LLeMbas Desktop: the server in a window, the CLI's agent on this computer

Tauri 2, no Node. A first-run page chooses the server; then the window is
the server's web UI, whose pages get no IPC. The bundled LLeMbas CLI
(fetched and signature-checked by scripts/fetch-cli.sh) links the computer
with 'lembas login --json' and runs as 'lembas service' while the app runs.
A tray menu starts and stops it. Linux packages from GitHub Actions on a tag.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ui/app.js

@@ -0,0 +1,74 @@
+// The first-run page. It talks to the app over Tauri's IPC — four commands, see src-tauri/src/lib.rs.
+// The server's own pages never get this: they are remote content with no capability.
+"use strict"
+
+const { invoke } = window.__TAURI__.core
+const { listen } = window.__TAURI__.event
+
+const $ = (id) => document.getElementById(id)
+
+const AGENT = {
+  off: () => ["The agent is off.", ""],
+  not_linked: () => ["This computer is not linked to the server yet.", ""],
+  starting: () => ["The agent is starting…", ""],
+  running: () => ["The agent is running: agent chats can use this computer.", "is-ok"],
+  elsewhere: (pid) => [`A LLeMbas CLI service already runs here (pid ${pid}); it is this computer's agent.`, "is-ok"],
+  failed: (why) => [`The agent stopped: ${why}. Trying again shortly.`, "is-error"],
+}
+
+function render(s) {
+  $("version").textContent = s.version
+  if (s.server && !$("address").value) $("address").value = s.server
+  $("agent-section").hidden = !s.server
+  const [text, cls] = (AGENT[s.agent.state] ?? AGENT.off)(s.agent.detail)
+  const status = $("agent-status")
+  status.textContent = text
+  status.className = `status ${cls}`
+  $("link").textContent = s.linked ? "Link again" : "Link this computer"
+  $("toggle").textContent = s.agent_wanted ? "Stop the agent" : "Start the agent"
+  $("toggle").disabled = !s.linked && !s.agent_wanted
+}
+
+async function refresh() {
+  render(await invoke("get_status"))
+}
+
+$("server-form").addEventListener("submit", async (e) => {
+  e.preventDefault()
+  const hint = $("server-hint")
+  const button = e.target.querySelector("button")
+  button.disabled = true
+  hint.className = "hint"
+  hint.textContent = "Looking for a LLeMbas server there…"
+  try {
+    await invoke("set_server", { address: $("address").value })
+    // The window now shows the server.
+  } catch (err) {
+    hint.className = "hint is-error"
+    hint.textContent = String(err)
+  } finally {
+    button.disabled = false
+  }
+})
+
+$("link").addEventListener("click", async () => {
+  try {
+    await invoke("link_computer")
+  } catch (err) {
+    $("agent-status").className = "status is-error"
+    $("agent-status").textContent = String(err)
+  }
+})
+
+$("toggle").addEventListener("click", async () => {
+  const s = await invoke("get_status")
+  await invoke("set_agent", { on: !s.agent_wanted })
+})
+
+$("open").addEventListener("click", async () => {
+  const s = await invoke("get_status")
+  if (s.server) await invoke("set_server", { address: s.server })
+})
+
+listen("status", (e) => render(e.payload))
+refresh()