Go: add parameter parsing of list chats (#14026)

### What problem does this PR solve?

As title.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

internal/handler/chat.go

@@ -56,8 +56,32 @@ func (h *ChatHandler) ListChats(c *gin.Context) {
 	}
 	userID := user.ID
 
+	// Parse query parameters
+	keywords := c.Query("keywords")
+
+	page := 0
+	if pageStr := c.Query("page"); pageStr != "" {
+		if p, err := strconv.Atoi(pageStr); err == nil && p > 0 {
+			page = p
+		}
+	}
+
+	pageSize := 0
+	if pageSizeStr := c.Query("page_size"); pageSizeStr != "" {
+		if ps, err := strconv.Atoi(pageSizeStr); err == nil && ps > 0 {
+			pageSize = ps
+		}
+	}
+
+	orderby := c.DefaultQuery("orderby", "create_time")
+
+	desc := true
+	if descStr := c.Query("desc"); descStr != "" {
+		desc = descStr != "false"
+	}
+
 	// List chats - default to valid status "1" (same as Python StatusEnum.VALID.value)
-	result, err := h.chatService.ListChats(userID, "1")
+	result, err := h.chatService.ListChats(userID, keywords, "1", page, pageSize, orderby, desc)
 	if err != nil {
 		c.JSON(http.StatusInternalServerError, gin.H{
 			"code":    500,

internal/service/chat.go

@@ -59,7 +59,7 @@ type ListChatsResponse struct {
 }
 
 // ListChats list chats for a user
-func (s *ChatService) ListChats(userID string, status string) (*ListChatsResponse, error) {
+func (s *ChatService) ListChats(userID, status, keywords string, page, pageSize int, orderby string, desc bool) (*ListChatsResponse, error) {
 	// Get tenant IDs by user ID
 	tenantIDs, err := s.userTenantDAO.GetTenantIDsByUserID(userID)
 	if err != nil {
@@ -81,6 +81,21 @@ func (s *ChatService) ListChats(userID string, status string) (*ListChatsRespons
 		return nil, err
 	}
 
+	total := int64(len(chats))
+
+	if page > 0 && pageSize > 0 {
+		start := (page - 1) * pageSize
+		end := start + pageSize
+		if start < int(total) {
+			if end > int(total) {
+				end = int(total)
+			}
+			chats = chats[start:end]
+		} else {
+			chats = []*entity.Chat{}
+		}
+	}
+
 	// Enrich with knowledge base names
 	chatsWithKBNames := make([]*ChatWithKBNames, 0, len(chats))
 	for _, chat := range chats {