VPN connection log: who connected and when

WireGuard has no connect events, only the last handshake and byte counters.
awg-ctrl now checks them every 30 s and writes conn_log in users.db: connect
at the first handshake, disconnect at the last activity (the last tick the
counters moved), with the session length and traffic, plus peer_seen, the
last time each peer was online. Open sessions are restored from the database,
so a restart adds no duplicates; a down interface is not a disconnect; a peer
removed mid-session is closed. Events keep the name, owner and VPN IP as of
that moment and live 90 days. Client public IPs are not recorded.

GET /api/connlog serves the events and the per-peer last-seen list. The panel
fetches it from the selected server at /ui/connlog and fills in master key
labels and device names for sen:// peers. A new "Подключения" tab shows the
event feed with search and paging, and "who was online when", including
those who never connected.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013bNGYiDst62wH3ZGTRPFLJ

internal/ui/server.go

@@ -879,6 +879,7 @@ func (a *App) routes() *Router {
 	app.Use("/ui/metrics-token", auth)
 	app.Mount("/ui/metrics-token", a.metrics.router())
 	app.Get("/metrics", a.metrics.requireToken, a.metrics.handler)
+	app.Get("/ui/connlog", auth, a.connlog)
 	app.Use("/ui/monitor", auth)
 	app.Mount("/ui/monitor", a.monitor.router())
 	// Перенос панели: приём архива — без JWT, его пускает только ключ из кода переноса.