Phase 2: ECS foundation — world, components, systems, bridge

- bitECS world with time tracking (delta, elapsed, tick)
- 5 components: Position, Velocity, SpriteRef, Health, ChemicalComposition
- Movement system (velocity * delta) + bounce system (boundary reflection)
- Health system with damage, healing, death detection
- Entity factory (createGameEntity/removeGameEntity)
- Phaser bridge: polling sync creates/destroys/updates circle sprites
- GameScene: 20 colored circles bouncing at 60fps
- BootScene: click-to-start transition, version bump to v0.2.0
- 39 ECS unit tests passing (74 total)

Co-authored-by: Cursor <cursoragent@cursor.com>

src/scenes/BootScene.ts

@@ -30,29 +30,33 @@ export class BootScene extends Phaser.Scene {
 
     // Version
     this.add
-      .text(cx, cy + 80, 'v0.1.0 — Phase 0: Project Setup', {
+      .text(cx, cy + 80, 'v0.2.0 — Phase 2: ECS Foundation', {
         fontSize: '12px',
         color: '#333333',
         fontFamily: 'monospace',
       })
       .setOrigin(0.5);
 
-    // Pulsing indicator
-    const dot = this.add
-      .text(cx, cy + 120, '◉', {
-        fontSize: '24px',
+    // Click to start
+    const startText = this.add
+      .text(cx, cy + 120, '[ Click to start ]', {
+        fontSize: '16px',
         color: '#00ff88',
         fontFamily: 'monospace',
       })
       .setOrigin(0.5);
 
     this.tweens.add({
-      targets: dot,
-      alpha: 0.2,
+      targets: startText,
+      alpha: 0.3,
       duration: 1500,
       yoyo: true,
       repeat: -1,
       ease: 'Sine.easeInOut',
     });
+
+    this.input.once('pointerdown', () => {
+      this.scene.start('GameScene');
+    });
   }
 }