feat(websocket): integrate WebSocket support and refactor SSE handling

- Added WebSocket support by introducing a new WSHandler and related infrastructure.
- Replaced SSE implementations with WebSocket equivalents across message and QR code handlers.
- Updated service and repository layers to utilize WebSocket for real-time messaging.
- Removed obsolete SSE hub and related code, streamlining the application for WebSocket usage.
- Enhanced router to include WebSocket endpoints for real-time communication.

internal/handler/qrcode_handler.go

@@ -8,7 +8,7 @@ import (
 	"github.com/gin-gonic/gin"
 
 	"carrot_bbs/internal/pkg/response"
-	"carrot_bbs/internal/pkg/sse"
+	"carrot_bbs/internal/pkg/ws"
 	"carrot_bbs/internal/service"
 )
 
@@ -44,16 +44,16 @@ func (h *QRCodeHandler) GetQRCode(c *gin.Context) {
 	})
 }
 
-// SSEEvents SSE事件流
+// WSEvents WebSocket事件流
 // GET /api/v1/auth/qrcode/events?session_id=xxx
-func (h *QRCodeHandler) SSEEvents(c *gin.Context) {
+func (h *QRCodeHandler) WSEvents(c *gin.Context) {
 	sessionID := c.Query("session_id")
 	if sessionID == "" {
 		response.BadRequest(c, "session_id is required")
 		return
 	}
 
-	ch, cancel, replay := h.qrcodeService.GetSSEHub().Subscribe(sessionID, 0)
+	ch, cancel, replay := h.qrcodeService.GetWSHub().Subscribe(sessionID, 0)
 	defer cancel()
 
 	w := c.Writer
@@ -70,8 +70,8 @@ func (h *QRCodeHandler) SSEEvents(c *gin.Context) {
 	c.Status(http.StatusOK)
 	flusher.Flush()
 
-	writeEvent := func(ev sse.Event) bool {
-		data, err := sse.EncodeData(ev)
+	writeEvent := func(ev ws.Event) bool {
+		data, err := ws.EncodeData(ev)
 		if err != nil {
 			return false
 		}