fix: make news geotagging deterministic

dashboard/inject.mjs

@@ -83,16 +83,48 @@ const geoKeywords = {
   'IMF':[38.9,-77],'World Bank':[38.9,-77],'UN':[40.7,-74],
 };
 
-function geoTagText(text) {
+function escapeRegex(value) {
+  return value.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+}
+
+function geoKeywordRegex(keyword) {
+  const flags = keyword.length <= 3 && keyword === keyword.toUpperCase() ? 'u' : 'iu';
+  return new RegExp(`(^|[^\\p{L}\\p{N}])${escapeRegex(keyword)}(?=$|[^\\p{L}\\p{N}])`, flags);
+}
+
+const geoKeywordEntries = Object.entries(geoKeywords)
+  .sort((a, b) => b[0].length - a[0].length)
+  .map(([keyword, coords]) => ({ keyword, coords, pattern: geoKeywordRegex(keyword) }));
+
+export function geoTagText(text) {
   if (!text) return null;
-  for (const [keyword, [lat, lon]] of Object.entries(geoKeywords)) {
-    if (text.includes(keyword)) {
+  for (const { keyword, coords, pattern } of geoKeywordEntries) {
+    if (pattern.test(text)) {
+      const [lat, lon] = coords;
       return { lat, lon, region: keyword };
     }
   }
   return null;
 }
 
+function stableHash(value) {
+  let hash = 2166136261;
+  for (let i = 0; i < value.length; i++) {
+    hash ^= value.charCodeAt(i);
+    hash = Math.imul(hash, 16777619);
+  }
+  return hash >>> 0;
+}
+
+export function stableGeoJitter(key, axis) {
+  const bucket = stableHash(`${axis}:${key}`) / 0xffffffff;
+  return (bucket - 0.5) * 2;
+}
+
+function newsGeoKey(item) {
+  return `${item.source || ''}|${item.title || ''}|${item.date || ''}|${item.url || ''}`;
+}
+
 function sanitizeExternalUrl(raw) {
   if (!raw) return undefined;
   try {
@@ -235,8 +267,8 @@ export async function fetchAllNews() {
         source: item.source,
         date: item.date,
         url: item.url,
-        lat: geo.lat + (Math.random() - 0.5) * 2,
-        lon: geo.lon + (Math.random() - 0.5) * 2,
+        lat: geo.lat + stableGeoJitter(newsGeoKey(item), 'lat'),
+        lon: geo.lon + stableGeoJitter(newsGeoKey(item), 'lon'),
         region: geo.region
       });
     }