feat: polls with live voting via WebSocket

- /poll command opens creation modal (2-10 options)
- PollDisplay with vote bars, percentages, live WS updates
- Backend: polls/poll_options/poll_votes tables, Create/Get/Vote endpoints
- attachPolls enriches message list responses
- POLL_UPDATE broadcast on vote for real-time sync

cmd/server/main.go

@@ -226,6 +226,12 @@ func main() {
 								message.NewHandler(database.DB, hub, pushHandler, logger, permissionsChecker).RegisterRoutes(r)
 			})
 
+			// Polls
+			pollHandler := message.NewPollHandler(database.DB, hub, permissionsChecker)
+			r.Route("/polls", func(r chi.Router) {
+				pollHandler.RegisterRoutes(r)
+			})
+
 			// Per-channel notification settings
 			r.Route("/channels/{channelID}/notifications", func(r chi.Router) {
 				notification.NewHandler(database.DB, logger).RegisterRoutes(r)