feat: Claude Code Monitor — lanes, pipelines and a merged workspace

Internal SmartGift build of a Claude Code monitoring dashboard.

Lanes: a durable unit of parallel agent work, one per working directory,
tracked across session restarts. Managed lanes are git worktrees the
dashboard provisions and can reset or remove behind a three-check destroy
guard and a counted preflight; adopted lanes are directories you already
own and are never destroyable.

Pipelines: a lane moves through pipeline stages. A stage the agent declares
with evidence renders green; a stage inferred from the tool-event stream
renders dashed amber and never counts as done. Detection is forward-only
within a 30-minute window, and never writes the declared stage.

Workspace: one page at /run with a lane grid, the selected lane's pipeline,
and a full Claude console behind a disclosure.

sw.js

@@ -0,0 +1,50 @@
+/**
+ * @file sw.js
+ * @description Service worker for the project landing page — precaches the shell (index, favicon, OG image, manifest) and manages cache lifecycle for offline support.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+
+const CACHE_NAME = "landing-v1";
+const PRECACHE = ["./", "./index.html", "./favicon.svg", "./og-image.svg", "./manifest.json"];
+
+self.addEventListener("install", (event) => {
+  event.waitUntil(caches.open(CACHE_NAME).then((cache) => cache.addAll(PRECACHE)));
+  self.skipWaiting();
+});
+
+self.addEventListener("activate", (event) => {
+  event.waitUntil(
+    caches
+      .keys()
+      .then((keys) =>
+        Promise.all(keys.filter((k) => k !== CACHE_NAME).map((k) => caches.delete(k)))
+      )
+  );
+  self.clients.claim();
+});
+
+self.addEventListener("fetch", (event) => {
+  const { request } = event;
+  if (request.method !== "GET") return;
+
+  if (request.mode === "navigate") {
+    // Network-first for HTML
+    event.respondWith(fetch(request).catch(() => caches.match("./index.html")));
+    return;
+  }
+
+  // Cache-first for assets, lazy-cache on miss
+  event.respondWith(
+    caches.match(request).then(
+      (cached) =>
+        cached ||
+        fetch(request).then((response) => {
+          if (response.ok) {
+            const clone = response.clone();
+            caches.open(CACHE_NAME).then((cache) => cache.put(request, clone));
+          }
+          return response;
+        })
+    )
+  );
+});