fix(street-level): KartaView QA round — archived photos, connection budget, paging, ‹ ›

From two agentic QA passes (UX and failure modes):
- A line click opens the nearest photo that can be shown: archived photos
  (409; a HEAD says 200) and records without files are skipped, a few at
  most, else 'KartaView's photos here are archived'. ‹ › skip them too.
- api.kartaview.org is HTTP/1.1 (six connections): tiles take three,
  lookups two, sequence pages one, so a lookup never times out behind
  tiles; a timed-out lookup is asked once more; waits are capped at 10 s.
- Sequence pages follow photo ids, not the index: a photo's page is found
  by search, a neighbour page joins near an edge, so ‹ › neither skip at
  page edges nor loop past gaps. Pages are 500 photos (~1.2 MB).
- ‹ › open through the core without framing: loading, errors and cones
  behave as for any open; presses step on from the photo on its way; the
  ends disable up front.
- Cones ignore the hidden IMAGERY / SINCE filters; no 'Selected' swatch
  for a source whose lines never highlight; 'no KartaView photos in view';
  an unreadable tile is not cached as empty; a 0,0 fix is no photo; a
  failed lookup's error goes when another source is lit; the link goes
  through the image proxy; a stalled panorama shows its front view after
  15 s instead of 60.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/layers/streetLevel/index.test.mjs

@@ -818,3 +818,23 @@ test('an empty provider composition enables and tears down without acquiring ima
   layer.enable(viewer);
   assert.deepEqual(layer.getUIState().providers, []);
 });
+
+test('a failed lookup’s error goes when another source is lit; a provider can open an image without framing', async (t) => {
+  const failing = fakeProvider({
+    nearestImage: async () => {
+      throw new Error('KartaView did not answer in time — try again');
+    },
+  });
+  const other = fakeProvider({ id: 'other', pickPrefix: 'oth:' });
+  const { layer, viewer } = await enabledLayer(t, [failing, other]);
+  layer.attachViewerHost({});
+  await layer.openNearest({ lat: 1, lon: 1 });
+  assert.match(layer.getUIState().street.error, /did not answer/);
+  layer.setProviderEnabled('other', true);
+  await settle();
+  assert.equal(layer.getUIState().street.error, null);
+  // A provider's own open (KartaView's ‹ ›) can leave the camera alone.
+  await other.context().actions.openImage('img-1', { frame: false });
+  assert.deepEqual(other.calls.open, ['img-1']);
+  assert.equal(viewer.flights.started, 0);
+});