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_modules/autoprefixer/bin/autoprefixer

@@ -0,0 +1,22 @@
+#!/usr/bin/env node
+
+let mode = process.argv[2]
+if (mode === '--info') {
+  process.stdout.write(require('../')().info() + '\n')
+} else if (mode === '--version') {
+  process.stdout.write(
+    'autoprefixer ' + require('../package.json').version + '\n'
+  )
+} else {
+  process.stdout.write(
+    'autoprefix\n' +
+      '\n' +
+      'Options:\n' +
+      '  --info    Show target browsers and used prefixes\n' +
+      '  --version Show version number\n' +
+      '  --help    Show help\n' +
+      '\n' +
+      'Usage:\n' +
+      '  autoprefixer --info\n'
+  )
+}