fix: reserve Untitled Project name; rename project will trigger save immidiatly.

src/App.tsx

@@ -18,6 +18,8 @@ import type { RenderingEvent } from './core/audio-interface/KGOfflineRenderer';
 import { KGCore } from './core/KGCore';
 import { ConfigManager } from './core/config/ConfigManager';
 import { validateFunctionalChordsJSON } from './util/scaleUtil';
+import { KGProjectStorage } from './core/io/KGProjectStorage';
+import { RESERVED_PROJECT_NAME } from './util/projectNameUtil';
 
 function App() {
   // Enable global keyboard handler for copy/paste and undo/redo
@@ -42,6 +44,16 @@ function App() {
     hasInitialized.current = true;
 
     const initializeApp = async () => {
+      // Wipe the reserved "Untitled Project" OPFS folder on every startup so it stays ephemeral
+      try {
+        const storage = KGProjectStorage.getInstance();
+        if (await storage.exists(RESERVED_PROJECT_NAME)) {
+          await storage.delete(RESERVED_PROJECT_NAME);
+        }
+      } catch (error) {
+        console.warn('Could not clear Untitled Project folder on startup:', error);
+      }
+
       // Load the current project from KGCore
       loadProject(null);
 

src/components/Toolbar.tsx

@@ -2,7 +2,7 @@ import React from 'react';
 import './Toolbar.css';
 import { saveProject } from '../util/saveUtil';
 import { KGProjectStorage } from '../core/io/KGProjectStorage';
-import { isValidProjectName } from '../util/projectNameUtil';
+import { isValidProjectName, isReservedProjectName, RESERVED_PROJECT_NAME } from '../util/projectNameUtil';
 import { KGCore } from '../core/KGCore';
 import { useProjectStore } from '../stores/projectStore';
 import { DEBUG_MODE } from '../constants/uiConstants';
@@ -86,15 +86,43 @@ const Toolbar: React.FC = () => {
   // Export options
   const exportOptions = ["Export to KGStudio file", "Export to MIDI file", "Export to WAV", "Export to MP3"];
 
-  const handleProjectNameClick = () => {
+  const handleProjectNameClick = async () => {
     const newName = prompt("Enter project name:", projectName);
-    if (newName) {
+    if (!newName) return;
-      if (!isValidProjectName(newName)) {
+    if (!isValidProjectName(newName)) {
-        window.alert("Invalid project name. Only letters, numbers, spaces, hyphens, underscores, periods, and parentheses are allowed.");
+      window.alert("Invalid project name. Only letters, numbers, spaces, hyphens, underscores, periods, and parentheses are allowed.");
+      return;
+    }
+    if (isReservedProjectName(newName)) {
+      window.alert(`"${RESERVED_PROJECT_NAME}" is a reserved project name. Please choose a different name.`);
+      return;
+    }
+
+    // Conflict check: only relevant when targeting a different OPFS folder
+    if (newName !== savedProjectName) {
+      const storage = KGProjectStorage.getInstance();
+      const exists = await storage.exists(newName);
+      if (exists) {
+        const confirmed = window.confirm(
+          `Project "${newName}" already exists. Do you want to overwrite it?`
+        );
+        if (!confirmed) return;
+        // Confirmed: update in-memory name then save immediately, overwriting the existing project
+        setProjectName(newName);
+        await saveProject(newName, savedProjectName, setStatus, (finalName) => {
+          setSavedProjectName(finalName);
+          if (finalName !== newName) setProjectName(finalName);
+        }, true /* forceOverwrite */);
         return;
       }
-      setProjectName(newName);
     }
+
+    // Name is available — update and save immediately
+    setProjectName(newName);
+    await saveProject(newName, savedProjectName, setStatus, (finalName) => {
+      setSavedProjectName(finalName);
+      if (finalName !== newName) setProjectName(finalName);
+    });
   };
 
   // Common project loading logic extracted for reuse

src/core/io/KGProjectStorage.ts

@@ -351,11 +351,11 @@ export class KGProjectStorage {
    * Used when the user renames the project and saves. Handles the case where the
    * old folder doesn't exist yet (new project never saved).
    */
-  public async saveWithRename(oldName: string, newName: string, data: KGProject): Promise<void> {
+  public async saveWithRename(oldName: string, newName: string, data: KGProject, overwrite: boolean = false): Promise<void> {
     this.ensureInitialized();
 
     // Save project JSON to the new folder
-    await this.save(newName, data, false);
+    await this.save(newName, data, overwrite);
 
     // Migrate media files only if the old folder exists
     if (await this.exists(oldName)) {

src/util/projectNameUtil.ts

@@ -9,6 +9,12 @@ const VALID_PROJECT_NAME_REGEX = /^[a-zA-Z0-9 \-_.()\u00C0-\u024F]+$/;
  */
 const DISALLOWED_CHARS_REGEX = /[^a-zA-Z0-9 \-_.()\u00C0-\u024F]/g;
 
+/**
+ * The reserved project name used for unsaved/new projects.
+ * Users cannot rename a project to this name, and its OPFS folder is wiped on every startup.
+ */
+export const RESERVED_PROJECT_NAME = "Untitled Project";
+
 /**
  * Validate whether a project name contains only allowed characters.
  * Does NOT check for empty string — caller should check that separately.
@@ -19,6 +25,13 @@ export function isValidProjectName(name: string): boolean {
   return VALID_PROJECT_NAME_REGEX.test(name);
 }
 
+/**
+ * Returns true if the given name matches the reserved "Untitled Project" name.
+ */
+export function isReservedProjectName(name: string): boolean {
+  return name.trim() === RESERVED_PROJECT_NAME;
+}
+
 /**
  * Sanitize a project name by replacing disallowed characters with underscores,
  * collapsing consecutive underscores/spaces, and trimming.
@@ -37,7 +50,7 @@ export function sanitizeProjectName(name: string): string {
 
   // If everything was stripped, provide a fallback
   if (sanitized.length === 0) {
-    sanitized = 'Untitled Project';
+    sanitized = RESERVED_PROJECT_NAME;
   }
 
   return sanitized;

src/util/saveUtil.ts

@@ -1,5 +1,6 @@
 import { KGProjectStorage, DuplicateEntryError } from '../core/io/KGProjectStorage';
 import { KGCore } from '../core/KGCore';
+import { RESERVED_PROJECT_NAME } from './projectNameUtil';
 
 /**
  * Save project utility function.
@@ -17,14 +18,27 @@ export const saveProject = async (
   savedProjectName: string,
   setStatus: (status: string) => void,
   onSaveSuccess: (finalName: string) => void,
+  forceOverwrite: boolean = false,
 ): Promise<boolean> => {
   const storage = KGProjectStorage.getInstance();
+
+  // Auto-rename reserved "Untitled Project" to "Untitled Project (1)", "(2)", etc.
+  if (projectName === RESERVED_PROJECT_NAME) {
+    let counter = 1;
+    let autoName = `${RESERVED_PROJECT_NAME} (${counter})`;
+    while (await storage.exists(autoName)) {
+      counter++;
+      autoName = `${RESERVED_PROJECT_NAME} (${counter})`;
+    }
+    projectName = autoName;
+  }
+
   const isRename = savedProjectName !== projectName;
 
   if (isRename) {
-    // Determine the target name, resolving conflicts automatically
+    // Determine the target name; skip conflict resolution when caller already confirmed overwrite
     let targetName = projectName;
-    if (await storage.exists(projectName)) {
+    if (!forceOverwrite && await storage.exists(projectName)) {
       targetName = await storage.resolveUniqueName(projectName);
     }
 
@@ -33,6 +47,7 @@ export const saveProject = async (
         savedProjectName,
         targetName,
         KGCore.instance().getCurrentProject(),
+        forceOverwrite,
       );
 
       const statusMsg =