refactor(street-level): drop hover, legend and byte-budget cache; flatten the provider directory

- No pointer cursor over coverage lines (no other layer has one); a click
  test replaces the hover tests.
- No legend: one source, one colour.
- The on-globe credit lives in index.js; credits.js is gone.
- Billboard glyphs are SVG data URLs with the same geometry, so tests need
  no canvas stub.
- The tile cache keeps the 120 most recently used tiles, same 24 h TTL,
  instead of a byte budget; listTileLayers was test-only.
- providers/mapillary/ is flattened into the layer and its policy merged
  into one policy.js; the source's method list is a literal in the catalog.
- One fakeCesiumViewer for the layer tests.
- The fixture gate keeps the steps the unit tests do not cover: coverage and
  credit, a rejected key, line -> cone -> photo, close, a keyless page.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

src/ui/streetLevelControls.js

@@ -24,8 +24,8 @@ const setAttr = (node, key, value) => {
 };
 
 /**
- * Fills the Street Level panel body: filters, legend and viewer. The panel
- * chrome itself belongs to the application shell.
+ * Fills the Street Level panel body: filters and viewer. The panel chrome
+ * itself belongs to the application shell.
  */
 export class StreetLevelControls {
   constructor({ root, layer, actions }) {
@@ -58,7 +58,6 @@ export class StreetLevelControls {
       errorText: byId('sl-error-text'),
       sinceRange: byId('sl-since'),
       sinceLabel: byId('sl-since-label'),
-      legend: byId('sl-legend'),
       viewerWrap: byId('sl-viewer-wrap'),
       viewerExpand: byId('sl-viewer-expand'),
       viewerClose: byId('sl-viewer-close'),
@@ -376,7 +375,6 @@ export class StreetLevelControls {
         setAttr(el.sinceRange, 'aria-valuetext', view.since.label);
       }
     }
-    setProp(el.legend, 'hidden', !view.legend);
   }
 
   _renderViewer(view) {

src/ui/streetLevelControls.test.mjs

@@ -223,7 +223,6 @@ function panelDom({ fullscreen = true, popover = false } = {}) {
     add(controls, 'button', { dataset: { slPano: pano } });
   add(controls, 'input', { id: 'sl-since' });
   add(controls, 'output', { id: 'sl-since-label' });
-  add(root, 'ul', { id: 'sl-legend' });
   add(root, 'div', { id: 'sl-coverage-meta' });
   return { document, root, wrap };
 }
@@ -475,11 +474,6 @@ test('a layer that is on with Mapillary switched off reads OFF, and the pill bri
       dom.root.querySelector('#sl-coverage-meta').textContent,
       /Mapillary is off in this view/,
     );
-    assert.equal(
-      dom.root.querySelector('#sl-legend').hidden,
-      true,
-      'no legend',
-    );
     status.click();
     await settle();
     assert.deepEqual(calls.setParams, [

src/ui/streetLevelPresentation.js

@@ -130,7 +130,6 @@ export function presentStreetLevelPanel(state, { now = Date.now() } = {}) {
         null,
     filter: { pano: filter.pano, sinceDays: Number(filter.sinceDays) || 0 },
     since: presentSince(filter.sinceDays, now),
-    legend: state.providerOn !== false,
     viewer: presentViewer(state),
     meta: presentMeta(state),
   };

src/ui/styles/street-level.css

@@ -118,7 +118,7 @@
   color: #ff8a80;
 }
 
-/* ── Filters and legend ──────────────────────────────────────────────────── */
+/* ── Filters ──────────────────────────────────────────────────── */
 .sl-filters {
   display: flex;
   align-items: center;
@@ -196,42 +196,6 @@
   color: var(--text-primary);
 }
 
-.sl-legend {
-  display: flex;
-  flex-wrap: wrap;
-  gap: 4px 12px;
-  margin: 0;
-  padding: 0;
-  list-style: none;
-}
-
-.sl-legend li {
-  display: inline-flex;
-  align-items: center;
-  gap: 6px;
-  font-family: var(--font-mono);
-  font-size: var(--sl-text);
-  letter-spacing: 0.06em;
-  color: var(--text-secondary);
-}
-
-.sl-legend[hidden] {
-  display: none;
-}
-
-.sl-legend-swatch {
-  width: 14px;
-  height: 3px;
-  border-radius: 2px;
-  display: inline-block;
-  background: var(--sl-green);
-}
-
-/* COLORS.selected in src/layers/streetLevel/policy.js */
-.sl-legend-swatch.is-selected {
-  background: #00d4ff;
-}
-
 /* ── Embedded viewer ─────────────────────────────────────────────────────── */
 .sl-viewer-wrap {
   position: relative;

src/ui/templates/layer-panels.html

@@ -124,10 +124,6 @@
             <output id="sl-since-label" class="sl-since-label" for="sl-since">ANY DATE</output>
           </div>
         </fieldset>
-        <ul id="sl-legend" class="sl-legend" aria-label="Coverage colours">
-          <li><i class="sl-legend-swatch"></i><span>Mapillary</span></li>
-          <li><i class="sl-legend-swatch is-selected"></i><span>Selected</span></li>
-        </ul>
         <div id="sl-coverage-meta" class="sl-meta"></div>
       </div>
     </div>