feat: safely merge partial persistent updates and update hide ui script

internal/sdkserver/api.go

@@ -312,7 +312,16 @@ func apiPersistentData(w http.ResponseWriter, r *http.Request) {
 			return
 		}
 
-		out, _ := json.MarshalIndent(parsed, "", "  ")
+		// Merge into existing persistent file so partial updates (e.g. lineups or switches) preserve other settings
+		existing := make(map[string]any)
+		if raw, err := os.ReadFile("persistent"); err == nil {
+			_ = json.Unmarshal(raw, &existing)
+		}
+		for k, v := range parsed {
+			existing[k] = v
+		}
+
+		out, _ := json.MarshalIndent(existing, "", "  ")
 		if err := os.WriteFile("persistent", out, 0o644); err != nil {
 			writeJSON(w, map[string]any{"error": "failed to write persistent: " + err.Error(), "status": 500})
 			return