feat: implement 13 features — auto-reconnect, notifications, bulk actions, latency, traffic, theme, export/import, scheduled backups, peer lookup, SSH auto-reconnect, log filters, keyboard shortcut, and readyTimeout default

- Change readyTimeoutMs default from 0 to 30000 in both state files
- Register Alt+Shift+H keyboard shortcut via manifest _execute_action command
- Add severity filter buttons (All/Info/Warn/Error) and Download .txt to Logs page; background logs.js now tags entries with proper level field
- Fire browser notifications on tunnelError events (notifyOnTunnelError setting)
- Add exponential-backoff auto-reconnect for virtual hosts and service tunnels (tunnelAutoReconnect setting, 5s–120s backoff)
- Add backupIntervalHours setting and scheduled auto-backup timer in message-router.js
- Add TCP connect latency badges to Virtual Hosts and Service Tunnels tables via new pingTunnel native message
- Add bytesIn/bytesOut/requests counters to https-proxy.js; expose in Overview status bar via getState
- Add Export/Import connection configs (JSON, no CA key) in Settings
- Add autoReconnect flag and exponential-backoff reconnect to SSH connection cards
- Add light theme CSS variables and theme toggle in Settings (persisted to localStorage)
- Add checkbox column and bulk Stop/Remove actions to Virtual Hosts, Service Tunnels, and Servers tables
- Add Peer Lookup UI card on Overview page using existing lookup message handler

extension/dashboard/pages/overview.js

@@ -222,6 +222,11 @@ function updateDashboard(state) {
   setText('ovCaLabel',      state.caInstalled ? 'Installed & trusted' : 'Not installed');
   setText('ovProxyLabel',   state.proxyPort        != null ? `port ${state.proxyPort}`        : '—');
   setText('ovConnectLabel', state.connectProxyPort != null ? `port ${state.connectProxyPort}` : '—');
+  if (state.trafficStats) {
+    const { bytesIn, bytesOut, requests } = state.trafficStats;
+    const fmt = (n) => n >= 1048576 ? (n / 1048576).toFixed(1) + ' MB' : n >= 1024 ? (n / 1024).toFixed(1) + ' KB' : n + ' B';
+    setText('ovTrafficLabel', `↑ ${fmt(bytesIn)} ↓ ${fmt(bytesOut)} (${requests} req)`);
+  }
 
   const lu = $('overviewLastUpdated');
   if (lu) lu.textContent = 'Updated ' + new Date().toLocaleTimeString();