优化日本绘图

public/js/app.js

@@ -1190,8 +1190,8 @@
         'new york corp': [-74.0060, 40.7128],
         'san francisco': [-122.4194, 37.7749],
         'los angeles': [-118.2437, 34.0522],
-        'japan': [138.2529, 36.2048],
-        'jp': [138.2529, 36.2048],
+        'japan': [139.6917, 35.6895],
+        'jp': [139.6917, 35.6895],
         'tokyo': [139.6917, 35.6895],
         'singapore': [103.8198, 1.3521],
         'sg': [103.8198, 1.3521],

server/geo-service.js

@@ -18,7 +18,7 @@ const enableExternalGeoLookup = process.env.ENABLE_EXTERNAL_GEO_LOOKUP === 'true
 function normalizeGeo(geo) {
   if (!geo) return geo;
 
-  // Custom normalization for TW to "Taipei, China" with Taipei coordinates
+  // Custom normalization for TW to "Taipei, China" and JP to "Tokyo"
   const country = (geo.country || geo.country_code || '').toUpperCase();
   if (country === 'TW') {
     return {
@@ -31,6 +31,17 @@ function normalizeGeo(geo) {
       latitude: 25.0330,
       longitude: 121.5654
     };
+  } else if (country === 'JP') {
+    return {
+      ...geo,
+      city: 'Tokyo',
+      country: 'JP',
+      country_name: 'Japan',
+      // Force Tokyo coordinates for consistent 2D plotting
+      loc: '35.6895,139.6917',
+      latitude: 35.6895,
+      longitude: 139.6917
+    };
   }
   return geo;
 }