feat: Add presence heartbeat for Matrix online status

- matrix-gateway: POST /internal/matrix/presence/online endpoint
- usePresenceHeartbeat hook with activity tracking
- Auto away after 5 min inactivity
- Offline on page close/visibility change
- Integrated in MatrixChatRoom component

node-network-app/node_modules/fastq/example.js

@@ -0,0 +1,14 @@
+'use strict'
+
+/* eslint-disable no-var */
+
+var queue = require('./')(worker, 1)
+
+queue.push(42, function (err, result) {
+  if (err) { throw err }
+  console.log('the result is', result)
+})
+
+function worker (arg, cb) {
+  cb(null, 42 * 2)
+}