fix(satellites): prevent selecting satellites on far side of earth

- Add isSatelliteFrontFacing() to detect if satellite is on visible side
- Filter satellites in hover and click handlers by front-facing check
- Apply same logic as cables for consistent back-face culling

frontend/public/earth/js/main.js

@@ -14,7 +14,7 @@ import {
 } from './ui.js';
 import { createEarth, createClouds, createTerrain, createStars, createGridLines, toggleTerrain, getEarth } from './earth.js';
 import { loadGeoJSONFromPath, loadLandingPoints, handleCableClick, clearCableSelection, getCableLines, getCablesById, lockedCable as cableLocked, getCableState, setCableState, clearAllCableStates, applyLandingPointVisualState, resetLandingPointVisualState, getAllLandingPoints, getShowCables } from './cables.js';
-import { createSatellites, loadSatellites, updateSatellitePositions, toggleSatellites, toggleTrails, getShowSatellites, getSatelliteCount, selectSatellite, getSatelliteData, getSatellitePoints, setSatelliteRingState, updateLockedRingPosition, updateHoverRingPosition, getSatellitePositions, showPredictedOrbit, hidePredictedOrbit, updateBreathingPhase } from './satellites.js';
+import { createSatellites, loadSatellites, updateSatellitePositions, toggleSatellites, toggleTrails, getShowSatellites, getSatelliteCount, selectSatellite, getSatelliteData, getSatellitePoints, setSatelliteRingState, updateLockedRingPosition, updateHoverRingPosition, getSatellitePositions, showPredictedOrbit, hidePredictedOrbit, updateBreathingPhase, isSatelliteFrontFacing } from './satellites.js';
 import { setupControls, getAutoRotate, getShowTerrain, zoomLevel, setAutoRotate, toggleAutoRotate, resetView } from './controls.js';
 import { initInfoCard, showInfoCard, hideInfoCard, getCurrentType, setInfoCardNoBorder } from './info-card.js';
 
@@ -301,8 +301,11 @@ function onMouseMove(event, camera) {
     if (satPoints) {
       const satIntersects = raycaster.intersectObject(satPoints);
       if (satIntersects.length > 0) {
-        hoveredSatIndexFromIntersect = satIntersects[0].index;
-        hoveredSat = selectSatellite(hoveredSatIndexFromIntersect);
+        const satIndex = satIntersects[0].index;
+        if (isSatelliteFrontFacing(satIndex, camera)) {
+          hoveredSatIndexFromIntersect = satIndex;
+          hoveredSat = selectSatellite(hoveredSatIndexFromIntersect);
+        }
       }
     }
   }
@@ -440,14 +443,17 @@ function onClick(event, camera, renderer) {
     const clickY = event.clientY;
     
     let selectedIndex;
-    if (satIntersects.length > 1 && 
+    const frontFacingSats = satIntersects.filter(s => isSatelliteFrontFacing(s.index, camera));
+    if (frontFacingSats.length === 0) return;
+    
+    if (frontFacingSats.length > 1 && 
         now - lastSatClickTime < 500 &&
         Math.abs(clickX - lastSatClickPos.x) < 30 &&
         Math.abs(clickY - lastSatClickPos.y) < 30) {
-      const currentIdx = satIntersects.findIndex(s => s.index === lastSatClickIndex);
-      selectedIndex = satIntersects[(currentIdx + 1) % satIntersects.length].index;
+      const currentIdx = frontFacingSats.findIndex(s => s.index === lastSatClickIndex);
+      selectedIndex = frontFacingSats[(currentIdx + 1) % frontFacingSats.length].index;
     } else {
-      selectedIndex = satIntersects[0].index;
+      selectedIndex = frontFacingSats[0].index;
     }
     
     lastSatClickTime = now;

frontend/public/earth/js/satellites.js

@@ -415,6 +415,20 @@ export function getSatellitePositions() {
   return satellitePositions;
 }
 
+export function isSatelliteFrontFacing(index, camera) {
+  if (!earthObjRef || !camera) return true;
+  const positions = satellitePositions;
+  if (!positions || !positions[index]) return true;
+  
+  const satPos = positions[index].current;
+  if (!satPos) return true;
+  
+  const toCamera = new THREE.Vector3().subVectors(camera.position, earthObjRef.position).normalize();
+  const toSat = new THREE.Vector3().subVectors(satPos, earthObjRef.position).normalize();
+  
+  return toCamera.dot(toSat) < 0;
+}
+
 let earthObjRef = null;
 let sceneRef = null;