feat: add energy beam to Batcave terminal

Added a vertical energy beam with animated opacity and pulse effect to represent the connection between Timmy and the outside world. Fixes #86

app.js

@@ -1134,8 +1134,12 @@ document.addEventListener('keydown', (e) => {
   if (e.key === 'Escape') exitZoom();
 });
 
-// === PHOTO MODE ===
-let photoMode = false;
+    // Update energy beam pulse effect
+    beamPulseTime += 0.02;
+    beamMaterial.opacity = 0.5 + Math.sin(beamPulseTime) * 0.2;
+
+    // === PHOTO MODE ===
+    let photoMode = false;
 
 // Warp effect state
 let isWarping = false;
@@ -1210,6 +1214,9 @@ document.addEventListener('keydown', (e) => {
   }
 });
 
+// Animation variables for energy beam pulse effect
+let beamPulseTime = 0;
+
 // === RESIZE HANDLER ===
 window.addEventListener('resize', () => {
   camera.aspect = window.innerWidth / window.innerHeight;
@@ -1218,6 +1225,28 @@ window.addEventListener('resize', () => {
   composer.setSize(window.innerWidth, window.innerHeight);
 });
 
+// === BATCAVE TERMINAL ENERGY BEAM ===
+// Vertical energy beam from Batcave terminal shooting up into the sky
+const energyBeamGroup = new THREE.Group();
+energyBeamGroup.position.set(3, 0.1, 3); // Positioned at Batcave terminal area
+scene.add(energyBeamGroup);
+
+// Cylinder geometry for the energy beam
+const beamGeometry = new THREE.CylinderGeometry(0.2, 0.2, 50, 32, 32);
+
+// Emissive material with animated opacity
+const beamMaterial = new THREE.MeshBasicMaterial({
+  color: 0x00ffff,
+  transparent: true,
+  opacity: 0.7,
+  blending: THREE.AdditiveBlending,
+  side: THREE.DoubleSide
+});
+
+const energyBeam = new THREE.Mesh(beamGeometry, beamMaterial);
+energyBeam.rotation.x = Math.PI / 2; // Vertical orientation
+energyBeamGroup.add(energyBeam);
+
 // === SOVEREIGNTY METER ===
 // Holographic arc gauge floating above the platform; reads from sovereignty-status.json
 const sovereigntyGroup = new THREE.Group();