v0.27.0 (#44): LLM-placed named map point markers

- shared: 8 MarkerTypes + MARKER_TYPE_INFO (label/color/glyph); MapMarker;
  GameState.markers (required, [] at init); TurnResult.markers {add,remove};
  MarkerSpec/MarkerInfo; FNV-1a 4-char markerId; MAX_MARKERS=400.
- data: new public/region-centroids.json (1,800 anchors = largest-part centroid
  + spread ~0.1x min-bbox) built by new idempotent scripts/build-region-centroids.mjs.
- server: regions.ts centroid loader (public/ then dist/); engine applyTurnResult
  marker ops (remove -> owner-recompute -> add, jitter, cap, never throws);
  prompt documents the contract; buildUserPrompt carries markers; stub marker-free.
- client: WorldMap symbol layer rendered as canvas per-type icons (glyph CDN dead);
  hover tooltip shows name; click focuses owning nation.
- tests: 168 -> 189 (centroids script, regions centroids, db legacy, engine markers).

scripts/region-centroids.test.ts

@@ -0,0 +1,158 @@
+/**
+ * scripts/region-centroids.test.ts — validation for the committed
+ * `public/region-centroids.json` (built by `scripts/build-region-centroids.mjs`).
+ *
+ * The manifest maps each region key to the anchor point a map marker (v0.27,
+ * #44) is placed at: the centroid of the region's largest-area part, plus a
+ * `spread` (≈ 0.1 × that part's smallest bbox dimension, in degrees) that the
+ * engine uses to scatter multiple markers of one region around the centroid.
+ * It is a load-bearing data artifact for the marker placement path — this test
+ * pins its contract.
+ *
+ * Deliberately dependency-free: it reads the JSON with plain `fs`/`JSON.parse`
+ * and computes bbox checks by iterating coordinates directly (no `@turf`/
+ * geojson types, which would pull `@types/geojson` into the tsc program and
+ * break `WorldMap.tsx` — see the v0.17 note). Mirrors the style of
+ * `scripts/region-adjacency.test.ts`; the determinism test re-runs the (turf
+ * `.mjs`) builder and compares bytes, matching that the builder is idempotent.
+ */
+import { readFileSync } from 'node:fs';
+import { execFileSync } from 'node:child_process';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { describe, expect, it } from 'vitest';
+
+const here = path.dirname(fileURLToPath(import.meta.url));
+const root = path.resolve(here, '..');
+
+function readJson(rel: string): Record<string, unknown> {
+  return JSON.parse(readFileSync(path.join(root, rel), 'utf8'));
+}
+
+interface CentroidEntry {
+  lat: number;
+  lon: number;
+  spread: number;
+}
+
+/** All [lon, lat] coordinate pairs of a Polygon / MultiPolygon geometry. */
+function allCoords(geometry: { type?: string; coordinates?: unknown }): Array<[number, number]> {
+  const c = geometry?.coordinates as
+    | Array<Array<[number, number]>>
+    | Array<Array<Array<[number, number]>>>
+    | undefined;
+  if (!c) return [];
+  if (geometry?.type === 'Polygon') {
+    const rings = c as Array<Array<[number, number]>>;
+    const out: Array<[number, number]> = [];
+    for (const ring of rings) for (const p of ring) out.push(p);
+    return out;
+  }
+  if (geometry?.type === 'MultiPolygon') {
+    const polys = c as Array<Array<Array<[number, number]>>>;
+    const out: Array<[number, number]> = [];
+    for (const poly of polys) for (const ring of poly) for (const p of ring) out.push(p);
+    return out;
+  }
+  return [];
+}
+
+/** The bounding box [minLon, minLat, maxLon, maxLat] of a geometry. */
+function bboxOf(geometry: { type?: string; coordinates?: unknown }): [number, number, number, number] {
+  let minLon = Infinity;
+  let minLat = Infinity;
+  let maxLon = -Infinity;
+  let maxLat = -Infinity;
+  for (const [x, y] of allCoords(geometry)) {
+    if (x < minLon) minLon = x;
+    if (y < minLat) minLat = y;
+    if (x > maxLon) maxLon = x;
+    if (y > maxLat) maxLat = y;
+  }
+  return [minLon, minLat, maxLon, maxLat];
+}
+
+describe('region-centroids.json', () => {
+  const centroids = readJson('public/region-centroids.json') as Record<string, CentroidEntry>;
+  const manifest = readJson('public/region-keys.json') as Record<string, string>;
+  const geo = readJson('public/regions.geo.json') as {
+    features?: Array<{ id?: string | number; geometry?: { type?: string; coordinates?: unknown } }>;
+  };
+  const keys = Object.values(manifest);
+
+  // featureId -> feature, then regionKey -> feature (via the key manifest).
+  const featureByKey = new Map<string, { geometry?: { type?: string; coordinates?: unknown } }>();
+  for (const f of geo.features ?? []) {
+    const key = manifest[String(f.id)];
+    if (key) featureByKey.set(key, f);
+  }
+
+  it('has exactly one entry per region key (same key set as region-keys.json)', () => {
+    expect(new Set(Object.keys(centroids))).toEqual(new Set(keys));
+    expect(Object.keys(centroids)).toHaveLength(1800);
+  });
+
+  it('every entry is a finite { lat, lon, spread } with a non-negative spread, in world bounds', () => {
+    for (const [k, v] of Object.entries(centroids)) {
+      expect(Number.isFinite(v.lat), `non-finite lat for ${k}`).toBe(true);
+      expect(Number.isFinite(v.lon), `non-finite lon for ${k}`).toBe(true);
+      expect(Number.isFinite(v.spread), `non-finite spread for ${k}`).toBe(true);
+      expect(v.spread >= 0, `negative spread for ${k}`).toBe(true);
+      expect(v.lat >= -90 && v.lat <= 90, `lat out of range for ${k}: ${v.lat}`).toBe(true);
+      expect(v.lon >= -180 && v.lon <= 180, `lon out of range for ${k}: ${v.lon}`).toBe(true);
+    }
+  });
+
+  it('each centroid lies inside its region feature bounding box', () => {
+    // The recorded point is the centroid of the LARGEST part, which is a subset
+    // of the whole feature, so it must fall inside the feature's overall bbox.
+    let checked = 0;
+    for (const [key, c] of Object.entries(centroids)) {
+      const feat = featureByKey.get(key);
+      if (!feat?.geometry) continue;
+      const [minLon, minLat, maxLon, maxLat] = bboxOf(feat.geometry);
+      const eps = 1e-4; // allow for the 6-dp rounding in the builder
+      expect(
+        c.lat >= minLat - eps && c.lat <= maxLat + eps,
+        `lat ${c.lat} outside bbox [${minLat}, ${maxLat}] for ${key}`,
+      ).toBe(true);
+      expect(
+        c.lon >= minLon - eps && c.lon <= maxLon + eps,
+        `lon ${c.lon} outside bbox [${minLon}, ${maxLon}] for ${key}`,
+      ).toBe(true);
+      checked++;
+    }
+    expect(checked).toBe(1800);
+  });
+
+  it('spot-checks a couple of well-known anchors land in the right place', () => {
+    // Region keys are sub-national (states/provinces), so we spot-check a few
+    // whose geography is unambiguous. A gross error in the centroid method
+    // (e.g. averaging across all parts of a large multi-part region, or a
+    // lon/lat swap) would land one of these far off.
+    const near = (k: string, lat: number, lon: number, tol: number) => {
+      const c = centroids[k];
+      expect(c, `missing centroid for ${k}`).toBeDefined();
+      expect(Math.abs(c!.lat - lat)).toBeLessThan(tol);
+      expect(Math.abs(c!.lon - lon)).toBeLessThan(tol);
+    };
+    near('ain-lqtt', 46.16, 4.8, 0.5); // FR-01 — eastern France
+    near('california-kikh', 36.87, -120.67, 0.7); // US-CA — central California
+    near('alberta-zopq', 52.09, -116.94, 1.5); // CA-AB — Alberta (large province)
+    near('acre-ekzw', -9.49, -71.11, 0.5); // BR-AC — western Brazil
+  });
+
+  it('is deterministic: re-running the builder rewrites a byte-identical file', () => {
+    const file = path.join(root, 'public', 'region-centroids.json');
+    const before = readFileSync(file, 'utf8');
+    // The builder is cwd-independent (it resolves the repo root from its own
+    // location) and idempotent: same input files + pure turf + fixed rounding
+    // + stable insertion order → identical bytes.
+    execFileSync(process.execPath, [path.join(root, 'scripts', 'build-region-centroids.mjs')], {
+      cwd: root,
+      stdio: 'pipe',
+    });
+    const after = readFileSync(file, 'utf8');
+    expect(after).toBe(before);
+  });
+});