fix(gateway): direct DB query and normalized UserID matching in BroadcastToServer

internal/gateway/hub.go

@@ -5,6 +5,7 @@ import (
 	"database/sql"
 	"encoding/json"
 	"log/slog"
+	"strings"
 	"sync"
 	"time"
 )
@@ -285,15 +286,30 @@ func (h *Hub) BroadcastToServer(serverID string, event Event) {
 		return
 	}
 
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	rows, err := h.db.QueryContext(ctx, `SELECT user_id FROM members WHERE server_id = $1`, serverID)
+	if err != nil {
+		h.logger.Error("failed to load server members", "server_id", serverID, "error", err)
+		return
+	}
+	defer rows.Close()
+
+	members := make(map[string]bool)
+	for rows.Next() {
+		var uid string
+		if err := rows.Scan(&uid); err == nil {
+			members[strings.ToLower(strings.TrimSpace(uid))] = true
+		}
+	}
+
 	h.mu.RLock()
 	defer h.mu.RUnlock()
 
 	for client := range h.clients {
-		servers, ok := h.userServers[client.UserID]
-		if !ok {
-			continue
-		}
-		if _, member := servers[serverID]; member {
+		cID := strings.ToLower(strings.TrimSpace(client.UserID))
+		if members[cID] {
 			select {
 			case client.send <- data:
 			default:
@@ -322,18 +338,19 @@ func (h *Hub) BroadcastToConversation(convID string, event Event) {
 	}
 	defer rows.Close()
 
-	members := make(map[string]struct{})
+	members := make(map[string]bool)
 	for rows.Next() {
 		var uid string
 		if err := rows.Scan(&uid); err == nil {
-			members[uid] = struct{}{}
+			members[strings.ToLower(strings.TrimSpace(uid))] = true
 		}
 	}
 
 	h.mu.RLock()
 	defer h.mu.RUnlock()
 	for client := range h.clients {
-		if _, ok := members[client.UserID]; ok {
+		cID := strings.ToLower(strings.TrimSpace(client.UserID))
+		if members[cID] {
 			select {
 			case client.send <- data:
 			default: