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.

server/routes/push.js

@@ -0,0 +1,53 @@
+/**
+ * @file Express router for managing push notifications, providing endpoints to retrieve the VAPID public key, subscribe/unsubscribe to push notifications, and send push notifications to all subscribers. It interacts with the database to store subscription details and uses a push library to send notifications.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+
+const { Router } = require("express");
+const { getPublicKey, sendPushToAll } = require("../lib/push");
+const { db } = require("../db");
+
+const router = Router();
+
+router.get("/vapid-public-key", (_req, res) => {
+  res.json({ publicKey: getPublicKey() });
+});
+
+router.post("/subscribe", (req, res) => {
+  const { endpoint, keys } = req.body;
+  if (!endpoint || !keys?.p256dh || !keys?.auth) {
+    return res.status(400).json({ error: { message: "Missing required fields" } });
+  }
+  db.prepare(
+    "INSERT OR REPLACE INTO push_subscriptions (endpoint, p256dh, auth) VALUES (?, ?, ?)"
+  ).run(endpoint, keys.p256dh, keys.auth);
+  res.json({ ok: true });
+});
+
+router.delete("/subscribe", (req, res) => {
+  const { endpoint } = req.body;
+  if (!endpoint) {
+    return res.status(400).json({ error: { message: "Missing endpoint" } });
+  }
+  db.prepare("DELETE FROM push_subscriptions WHERE endpoint = ?").run(endpoint);
+  res.json({ ok: true });
+});
+
+router.post("/send", async (req, res) => {
+  const { title, body } = req.body;
+  if (!title || !body) {
+    return res.status(400).json({ error: { message: "Missing title or body" } });
+  }
+  try {
+    // `result` tells the caller which surfaces actually fired:
+    //   { native: true|false, pushed: <count>, failed: <count> }
+    // so a silent "no subscribers, no Electron host" no-op stops looking like
+    // success on the client side.
+    const result = await sendPushToAll(db, title, body);
+    res.json({ ok: true, ...result });
+  } catch (err) {
+    res.status(500).json({ error: { message: err.message } });
+  }
+});
+
+module.exports = router;