优化中国台湾绘图

public/js/app.js

@@ -1176,8 +1176,8 @@
         'shanghai': [121.4737, 31.2304],
         'hong kong': [114.1694, 22.3193],
         'hk': [114.1694, 22.3193],
-        'taiwan': [120.9605, 23.6978],
-        'tw': [120.9605, 23.6978],
+        'taiwan': [121.5654, 25.0330],
+        'tw': [121.5654, 25.0330],
         'united states': [-95.7129, 37.0902],
         'us': [-95.7129, 37.0902],
         'us seattle': [-122.3321, 47.6062],

server/geo-service.js

@@ -18,13 +18,18 @@ const enableExternalGeoLookup = process.env.ENABLE_EXTERNAL_GEO_LOOKUP === 'true
 function normalizeGeo(geo) {
   if (!geo) return geo;
 
-  // Custom normalization for TW, HK, MO to "China, {CODE}"
-  const specialRegions = ['TW'];
-  if (specialRegions.includes(geo.country?.toUpperCase())) {
+  // Custom normalization for TW to "Taipei, China" with Taipei coordinates
+  const country = (geo.country || geo.country_code || '').toUpperCase();
+  if (country === 'TW') {
     return {
       ...geo,
-      city: `China, ${geo.country.toUpperCase()}`,
-      country_name: 'China'
+      city: 'Taipei',
+      country: 'TW',
+      country_name: 'China',
+      // Force Taipei coordinates for consistent 2D plotting
+      loc: '25.0330,121.5654',
+      latitude: 25.0330,
+      longitude: 121.5654
     };
   }
   return geo;