fix: keep a named place's own point in situation briefs

Brief sections received a named place as its bounding box, so they centered
on the box's middle: Tokyo's aircraft were sorted from a point in the
Pacific. Sections now receive the place name and resolve it like a direct
query, and place lookups are cached briefly so a brief resolves it once.

src/tools/places.test.mjs

@@ -0,0 +1,39 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { createGeocodePlaceService } from './places.js';
+
+const answer = {
+  results: [
+    {
+      formatted_address: 'Tokyo, Japan',
+      geometry: { location: { lat: 35.68, lng: 139.76 } },
+    },
+  ],
+};
+
+test('place lookups are cached by name for a while, and failures are not', async () => {
+  let clock = 0;
+  const requests = [];
+  let fail = true;
+  const places = createGeocodePlaceService({
+    now: () => clock,
+    cacheMs: 1000,
+    fetchImpl: async (url) => {
+      requests.push(url);
+      if (fail) return new Response(null, { status: 503 });
+      return Response.json(answer);
+    },
+  });
+  await assert.rejects(places.resolve('Tokyo'), /Geocode HTTP 503/);
+  fail = false;
+  const first = await places.resolve('Tokyo');
+  assert.deepEqual(first.point, { lat: 35.68, lon: 139.76 });
+  assert.equal(await places.resolve(' tokyo '), first);
+  assert.equal(requests.length, 2);
+  clock = 2000;
+  await places.resolve('Tokyo');
+  assert.equal(requests.length, 3);
+  const aborted = new AbortController();
+  aborted.abort();
+  await assert.rejects(places.resolve('Tokyo', { signal: aborted.signal }));
+});