fix(atlas): give every sub-national region a distinct code (#1217)

geoBoundaries fills shapeISO with the bare country code for some countries (every
Spanish region got "ESP", every Chinese "CHN", also Chile/Oman), so marking one
region lit up the whole country. build-atlas-geo.mjs now keeps shapeISO only when
it is a real "XX-..." subdivision code and otherwise synthesizes a unique
per-country id from the region name. Regenerated admin1.geojson.gz: Spain/China/
Chile/Oman now carry distinct region codes (countries with real codes, e.g.
Germany, are unchanged).

server/tests/unit/services/atlasBundle.test.ts

@@ -0,0 +1,36 @@
+import { describe, it, expect } from 'vitest';
+import fs from 'fs';
+import path from 'path';
+import zlib from 'zlib';
+
+// Data-integrity guard for the shipped Atlas region bundle. geoBoundaries fills
+// shapeISO with the bare country code for some countries (every Spanish region got
+// "ESP", every Chinese "CHN", also CL/OM), which made marking one region light up the
+// whole country (#1217). build-atlas-geo.mjs now synthesizes a unique per-region code
+// for those; this asserts the shipped bundle actually carries distinct codes.
+describe('Atlas admin1 region bundle (#1217)', () => {
+  const bundlePath = path.join(__dirname, '..', '..', '..', 'assets', 'atlas', 'admin1.geojson.gz');
+  const features = JSON.parse(zlib.gunzipSync(fs.readFileSync(bundlePath)).toString()).features as {
+    properties: { iso_a2: string | null; iso_3166_2: string };
+  }[];
+
+  const regions = (a2: string) => features.filter(f => f.properties.iso_a2 === a2);
+
+  it('ATLAS-BUNDLE-001 — previously-broken countries now have distinct region codes', () => {
+    for (const a2 of ['ES', 'CN', 'CL', 'OM']) {
+      const f = regions(a2);
+      expect(f.length, `${a2} should ship regions`).toBeGreaterThan(1);
+      expect(new Set(f.map(r => r.properties.iso_3166_2)).size, `${a2} region codes must be unique`).toBe(f.length);
+    }
+  });
+
+  it('ATLAS-BUNDLE-002 — countries with real ISO codes keep them and stay unique', () => {
+    for (const a2 of ['DE', 'FR', 'US']) {
+      const f = regions(a2);
+      expect(f.length).toBeGreaterThan(1);
+      // real ISO 3166-2 form, e.g. DE-BW
+      expect(f.some(r => /^[A-Z]{2}-[A-Z0-9]+$/.test(r.properties.iso_3166_2))).toBe(true);
+      expect(new Set(f.map(r => r.properties.iso_3166_2)).size).toBe(f.length);
+    }
+  });
+});