feat: persist global track visibility status and metronome status

src/core/KGProject.ts

@@ -54,11 +54,19 @@ export class KGProject {
   @WithDefault(1)
   private pianoRollZoom: number = 1;
 
+  @Expose()
+  @WithDefault(false)
+  private showGlobalTracks: boolean = false;
+
+  @Expose()
+  @WithDefault(false)
+  private isMetronomeEnabled: boolean = false;
+
   @Expose()
   @WithDefault(0)
   private projectStructureVersion: number = 0;
 
-  public static readonly CURRENT_PROJECT_STRUCTURE_VERSION: number = 15;
+  public static readonly CURRENT_PROJECT_STRUCTURE_VERSION: number = 16;
   
   @Expose()
   @Type(() => KGTrack, {
@@ -89,7 +97,7 @@ export class KGProject {
   private globalTracks: KGGlobalTrack[] = createDefaultGlobalTracks();
 
   // Constructor
-  constructor(name: string = RESERVED_PROJECT_NAME, maxBars: number = 32, currentBars: number = 0, bpm: number = TIME_CONSTANTS.DEFAULT_BPM, timeSignature: TimeSignature = { numerator: 4, denominator: 4 }, keySignature: KeySignature = "C major", selectedMode: string = "ionian", isLooping: boolean = false, loopingRange: [number, number] = [0, 0], barWidthMultiplier: number = 2, tracks: KGTrack[] = [], projectStructureVersion: number = KGProject.CURRENT_PROJECT_STRUCTURE_VERSION, pianoRollZoom: number = 1, globalTracks: KGGlobalTrack[] = createDefaultGlobalTracks()) {
+  constructor(name: string = RESERVED_PROJECT_NAME, maxBars: number = 32, currentBars: number = 0, bpm: number = TIME_CONSTANTS.DEFAULT_BPM, timeSignature: TimeSignature = { numerator: 4, denominator: 4 }, keySignature: KeySignature = "C major", selectedMode: string = "ionian", isLooping: boolean = false, loopingRange: [number, number] = [0, 0], barWidthMultiplier: number = 2, tracks: KGTrack[] = [], projectStructureVersion: number = KGProject.CURRENT_PROJECT_STRUCTURE_VERSION, pianoRollZoom: number = 1, globalTracks: KGGlobalTrack[] = createDefaultGlobalTracks(), showGlobalTracks: boolean = false, isMetronomeEnabled: boolean = false) {
     this.name = name;
     this.maxBars = maxBars;
     this.currentBars = currentBars;
@@ -104,6 +112,8 @@ export class KGProject {
     this.projectStructureVersion = projectStructureVersion;
     this.pianoRollZoom = pianoRollZoom;
     this.globalTracks = globalTracks;
+    this.showGlobalTracks = showGlobalTracks;
+    this.isMetronomeEnabled = isMetronomeEnabled;
   }
 
   // Getters
@@ -188,6 +198,22 @@ export class KGProject {
     return this.projectStructureVersion;
   }
 
+  public getShowGlobalTracks(): boolean {
+    return this.showGlobalTracks;
+  }
+
+  public setShowGlobalTracks(showGlobalTracks: boolean): void {
+    this.showGlobalTracks = showGlobalTracks;
+  }
+
+  public getIsMetronomeEnabled(): boolean {
+    return this.isMetronomeEnabled;
+  }
+
+  public setIsMetronomeEnabled(isMetronomeEnabled: boolean): void {
+    this.isMetronomeEnabled = isMetronomeEnabled;
+  }
+
   public getIsLooping(): boolean {
     return this.isLooping;
   }

src/core/io/KGProjectStorage.test.ts

@@ -163,6 +163,20 @@ describe('KGProjectStorage', () => {
     expect(loaded!.getPianoRollZoom()).toBe(5);
   });
 
+  it('preserves persisted global-track visibility and metronome state when saving and loading', async () => {
+    const project = createTestProject('Toggle Song');
+    project.setShowGlobalTracks(true);
+    project.setIsMetronomeEnabled(true);
+
+    await storage.save('Toggle Song', project);
+
+    const loaded = await storage.load('Toggle Song');
+
+    expect(loaded).not.toBeNull();
+    expect(loaded!.getShowGlobalTracks()).toBe(true);
+    expect(loaded!.getIsMetronomeEnabled()).toBe(true);
+  });
+
   it('preserves global tracks and marker regions when saving and loading', async () => {
     const project = createTestProject('Marker Song');
     const markerTrack = project.getGlobalTracks().find(track => track.getType() === GlobalTrackType.Marker);

src/core/project-upgrader/KGProjectUpgrader.ts

@@ -14,6 +14,7 @@ import { upgradeToV12 } from './upgradeToV12';
 import { upgradeToV13 } from './upgradeToV13';
 import { upgradeToV14 } from './upgradeToV14';
 import { upgradeToV15 } from './upgradeToV15';
+import { upgradeToV16 } from './upgradeToV16';
 
 /**
  * Upgrade the given project to the latest structure version, one version at a time.
@@ -93,6 +94,10 @@ export function upgradeProjectToLatest(project: KGProject): KGProject {
         workingProject = upgradeToV15(workingProject);
         break;
       }
+      case 16: {
+        workingProject = upgradeToV16(workingProject);
+        break;
+      }
       default: {
         // If an upgrader is missing, throw to prevent loading incompatible structures
         throw new Error(`No upgrader found for project structure version ${nextVersion}`);

src/core/project-upgrader/upgradeToV16.test.ts

@@ -0,0 +1,26 @@
+import { describe, expect, it } from 'vitest';
+import { KGProject } from '../KGProject';
+import { upgradeProjectToLatest } from './KGProjectUpgrader';
+import { upgradeToV16 } from './upgradeToV16';
+
+describe('upgradeToV16', () => {
+  it('defaults persisted UI/audio toggles to false for legacy projects', () => {
+    const project = new KGProject('Legacy', 32, 0, 125, undefined, undefined, undefined, undefined, [0, 0], 1, [], 15, 1, []);
+
+    upgradeToV16(project);
+
+    expect(project.getProjectStructureVersion()).toBe(16);
+    expect(project.getShowGlobalTracks()).toBe(false);
+    expect(project.getIsMetronomeEnabled()).toBe(false);
+  });
+
+  it('preserves existing persisted toggle values through the main upgrader path', () => {
+    const project = new KGProject('Legacy', 32, 0, 125, undefined, undefined, undefined, undefined, [0, 0], 1, [], 15, 1, [], true, true);
+
+    const upgraded = upgradeProjectToLatest(project);
+
+    expect(upgraded.getProjectStructureVersion()).toBe(KGProject.CURRENT_PROJECT_STRUCTURE_VERSION);
+    expect(upgraded.getShowGlobalTracks()).toBe(true);
+    expect(upgraded.getIsMetronomeEnabled()).toBe(true);
+  });
+});

src/core/project-upgrader/upgradeToV16.ts

@@ -0,0 +1,17 @@
+import { KGProject } from '../KGProject';
+
+export function upgradeToV16(project: KGProject): KGProject {
+  try {
+    if (typeof project.getShowGlobalTracks() !== 'boolean') {
+      project.setShowGlobalTracks(false);
+    }
+
+    if (typeof project.getIsMetronomeEnabled() !== 'boolean') {
+      project.setIsMetronomeEnabled(false);
+    }
+  } finally {
+    project.setProjectStructureVersion(16);
+  }
+
+  return project;
+}