refactor: update routes for unified API endpoints

- GET /api/v1/state replaces /me and /channels
- GET/POST /api/v1/messages replaces /poll, /channels/{ch}/messages, /dm/{nick}/messages
- GET /api/v1/history for scrollback
- DELETE /api/v1/channels/{name} replaces /channels/{channel}/part

internal/server/routes.go

@@ -53,23 +53,18 @@ func (s *Server) SetupRoutes() {
 	s.router.Route("/api/v1", func(r chi.Router) {
 		r.Get("/server", s.h.HandleServerInfo())
 		r.Post("/register", s.h.HandleRegister())
-		r.Get("/me", s.h.HandleMe())
+
+		// Unified state and message endpoints
+		r.Get("/state", s.h.HandleState())
+		r.Get("/messages", s.h.HandleGetMessages())
+		r.Post("/messages", s.h.HandleSendMessage())
+		r.Get("/history", s.h.HandleGetHistory())
 
 		// Channels
-		r.Get("/channels", s.h.HandleListChannels())
 		r.Get("/channels/all", s.h.HandleListAllChannels())
 		r.Post("/channels/join", s.h.HandleJoinChannel())
-		r.Delete("/channels/{channel}/part", s.h.HandlePartChannel())
+		r.Delete("/channels/{channel}", s.h.HandlePartChannel())
 		r.Get("/channels/{channel}/members", s.h.HandleChannelMembers())
-		r.Get("/channels/{channel}/messages", s.h.HandleGetMessages())
-		r.Post("/channels/{channel}/messages", s.h.HandleSendMessage())
-
-		// DMs
-		r.Get("/dm/{nick}/messages", s.h.HandleGetDMs())
-		r.Post("/dm/{nick}/messages", s.h.HandleSendDM())
-
-		// Polling
-		r.Get("/poll", s.h.HandlePoll())
 	})
 
 	// Serve embedded SPA