fix(recent-imagery): reject absent box edges instead of inventing zero degrees

src/layers/recentImagery/imagery-box-missing-edge.test.mjs

@@ -0,0 +1,16 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { validateBox, boxCentre } from './model.js';
+test('missing imagery edges do not turn into invented zero coordinates', () => {
+  for (const value of [null, undefined, '', ' ', false, true]) {
+    const box = { west: value, south: 0, east: 1, north: 1 };
+    assert.equal(validateBox(box).ok, false);
+    assert.equal(validateBox(box).reason, 'invalid');
+    assert.equal(boxCentre(box), null);
+  }
+  assert.equal(validateBox({ west: 0, south: 0, east: 1, north: 1 }).ok, true);
+  assert.equal(
+    validateBox({ west: '0', south: '0', east: '1', north: '1' }).ok,
+    true,
+  );
+});