explore: show width/opacity sliders in lines mode too

site/src/components/Explore.svelte

@@ -153,7 +153,7 @@
   function _updateHeatPaint(width: number, opacityPct: number) {
     if (!map) return;
     const p = _heatPaint(width, opacityPct);
-    for (const id of ['explore-heat-global', ...HEAT_TYPES.map(t => `explore-heat-${t}`)]) {
+    for (const id of ['explore-lines', 'explore-heat-global', ...HEAT_TYPES.map(t => `explore-heat-${t}`)]) {
       if (!map.getLayer(id)) continue;
       map.setPaintProperty(id, 'line-width',   p['line-width']);
       map.setPaintProperty(id, 'line-opacity', p['line-opacity']);
@@ -324,6 +324,7 @@
           <button class="pill small" class:active={heatmapMode === 'global'} onclick={() => heatmapMode = 'global'}>Global</button>
           <button class="pill small" class:active={heatmapMode === 'bytype'} onclick={() => heatmapMode = 'bytype'}>By type</button>
         </div>
+      {/if}
       <div class="slider-row">
         <span class="slider-label">Width</span>
         <input type="range" min="2" max="12" step="1" class="slider" bind:value={heatWidth} />
@@ -334,7 +335,6 @@
         <input type="range" min="3" max="30" step="1" class="slider" bind:value={heatOpacityPct} />
         <span class="slider-val">{heatOpacityPct}%</span>
       </div>
-      {/if}
     </section>
 
     <!-- Stats -->