fix(street-level): Panoramax IC8 review — line geometry budget, caches, attribution, tests

From a five-lens IC8 review (correctness, security, tests with mutation
testing, performance, UX):
- P0: over Paris at 12–60 km the unsimplified z10–z12 lines sent ~2M
  points to Cesium's ground-polyline builder (gigabytes of geometry; the
  tab hung). decode.js now simplifies lines (Douglas–Peucker, 4 tile
  units: 6–10% of the points), and lineCoverage gains an opt-in point
  budget (`maxPoints`, 10,000 a tile for Panoramax).
- Decoded coverage tiles are kept (KartaView's tile cache moves to the
  shared tileCache.js); a sequence's z15 picture lists are kept and load
  on their own connection; cones know their tiles from the start of a
  load, so a picture opening meanwhile re-centres them and ‹ › no longer
  restarts the load.
- The HD panorama loads only for the expanded viewer (a docked one on a
  dense screen asked for 3 MB originals) and is aborted when another
  photo opens; picture files over 48 MB or 16,384 px are refused; a
  bitmap no renderer took after a context loss is closed.
- A nearest lookup survives one of its two searches failing; only a
  timeout is retried; offline reads as unreachable; Retry-After is
  capped at five minutes; the search box stays on the map at ±180°;
  cones near both edges of a narrow (high-latitude) tile read both.
- Every producer is credited (app and photographer); with none to name,
  the caption says "via <instance>" rather than crediting the host.
- Esc anywhere in the docked viewer (toolbar, caption) clears the
  sequence before the panel takes it. A filter that hides every density
  dot says so; wording aligned ("coverage", "photo").
- Tests for every surviving mutant (Esc consumed, keepOrder and dot-size
  wiring, licence in the core, limiter aborts, radius floor, bbox corner,
  first-producer-only, byte and size caps), a limiter test, and a gate
  fixture that answers box searches and leaves out pictures facing away;
  the gate now clicks over the other sequence's pictures, so only the
  line click's own-sequence lookup can pass.

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

src/tooling/streetLevelQa.test.mjs

@@ -810,6 +810,18 @@ test('Panoramax fixtures: two sequences on one street, searches honour sequence
     true,
     'the second sequence is older',
   );
+  // A box has every picture in it, those looking away included; a place
+  // search leaves out pictures the point is behind (all look east).
+  const d = 0.0002;
+  const boxed = ask(
+    `bbox=${at.lon - d},${at.lat - d},${at.lon + d},${at.lat + d}&limit=100`,
+  );
+  assert.ok(boxed.some((p) => p.lon < at.lon) && boxed.some((p) => p.lon > at.lon));
+  const placed = ask(
+    `place_position=${at.lon},${at.lat}&place_distance=0-30&limit=50`,
+  );
+  assert.ok(placed.length > 0);
+  assert.ok(placed.every((p) => p.lon <= at.lon + 1e-7), 'none it is behind');
   const one = ask(`ids=${at.id}&limit=1`);
   assert.equal(one[0].id, at.id);
   // Its pictures, and only those, are served; HD downloads are counted.