Enforce pricelist write checks and auto-restart on DB settings change

internal/handlers/setup.go

@@ -148,6 +148,8 @@ func (h *SetupHandler) TestConnection(c *gin.Context) {
 
 // SaveConnection saves the connection settings and signals restart
 func (h *SetupHandler) SaveConnection(c *gin.Context) {
+	existingSettings, _ := h.localDB.GetSettings()
+
 	host := c.PostForm("host")
 	portStr := c.PostForm("port")
 	database := c.PostForm("database")
@@ -202,19 +204,29 @@ func (h *SetupHandler) SaveConnection(c *gin.Context) {
 		}
 	}
 
-	// Always restart to properly initialize all services with the new connection
-	restartRequired := h.restartSig == nil
+	settingsChanged := existingSettings == nil ||
+		existingSettings.Host != host ||
+		existingSettings.Port != port ||
+		existingSettings.Database != database ||
+		existingSettings.User != user ||
+		existingSettings.PasswordEncrypted != password
+
+	restartQueued := settingsChanged && h.restartSig != nil
 	c.JSON(http.StatusOK, gin.H{
 		"success":          true,
 		"message":          "Settings saved.",
-		"restart_required": restartRequired,
+		"restart_required": settingsChanged,
+		"restart_queued":   restartQueued,
 	})
 
 	// Signal restart after response is sent (if restart signal is configured)
-	if h.restartSig != nil {
+	if restartQueued {
 		go func() {
 			time.Sleep(500 * time.Millisecond) // Give time for response to be sent
-			h.restartSig <- struct{}{}
+			select {
+			case h.restartSig <- struct{}{}:
+			default:
+			}
 		}()
 	}
 }