feat: HUD hide/unhide tab + click-to-live chip

The side panel covered Cesium's clock dial, so a scrubbed clock was easy
to get stuck in with no visible way back — live-only layers (aircraft,
AIS ships) then look broken. Two escape hatches: a collapse tab riding
the panel edge (docks top-left when hidden, revealing the dial), and the
LIVE/SCRUBBED chip is now a button that snaps the clock straight back to
now from anywhere.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

css/style.css

@@ -86,6 +86,35 @@ html, body {
   background: rgba(255, 207, 80, 0.1);
   font-size: 9px;
 }
+/* The chip is a button now: click snaps the clock back to live. */
+#live-chip { cursor: pointer; }
+#live-chip[data-state="scrub"]:hover { background: rgba(255, 207, 80, 0.25); }
+
+/* ---- HUD hide/unhide tab ---- */
+#hud-toggle {
+  position: absolute;
+  top: 20px;
+  left: 306px; /* rides the panel's right edge */
+  z-index: 11;
+  width: 22px;
+  height: 30px;
+  padding: 0;
+  font: 11px ui-monospace, monospace;
+  color: var(--dim);
+  background: var(--panel);
+  border: 1px solid var(--border);
+  border-radius: 0 8px 8px 0;
+  border-left: none;
+  cursor: pointer;
+  transition: left 0.15s;
+}
+#hud-toggle:hover { color: var(--accent); }
+body.hud-hidden #hud { display: none; }
+body.hud-hidden #hud-toggle {
+  left: 14px;
+  border-radius: 8px;
+  border-left: 1px solid var(--border);
+}
 
 .modes {
   display: flex;

index.html

@@ -32,6 +32,9 @@
     </footer>
   </aside>
 
+  <!-- HUD collapse tab: rides the panel's edge; when hidden it docks top-left. -->
+  <button id="hud-toggle" type="button" title="Hide panel">◀</button>
+
   <div id="pick-overlay" hidden></div>
 
   <script type="module" src="js/main.js"></script>

js/main.js

@@ -77,6 +77,19 @@ function setMode(mode) {
 document.getElementById('mode-data').addEventListener('click', () => setMode('data'));
 document.getElementById('mode-photo').addEventListener('click', () => setMode('photo'));
 
+// ---- HUD hide/unhide + snap-to-live chip ----
+const hudToggle = document.getElementById('hud-toggle');
+hudToggle.addEventListener('click', () => {
+  const hidden = document.body.classList.toggle('hud-hidden');
+  hudToggle.textContent = hidden ? '▶' : '◀';
+  hudToggle.title = hidden ? 'Show panel' : 'Hide panel';
+});
+// Clicking LIVE/SCRUBBED snaps the clock back to now — the panel can cover the
+// Cesium clock dial, so this is the always-visible escape hatch from scrub mode.
+document.getElementById('live-chip').addEventListener('click', () => {
+  viewer.clock.currentTime = clampToWindow(Cesium.JulianDate.now());
+});
+
 // ---- portal to SOLARGOD (sibling orrery) ----
 // Deep-links to the solar-system app at GODSIGH's current sim moment via its
 // shared `#t=@<unixMs>` convention; the href is rebuilt fresh at click time.

js/ui.js

@@ -109,7 +109,7 @@ export function setLiveChip(isLive) {
   const chip = document.getElementById('live-chip');
   if (!chip) return;
   chip.textContent = isLive ? 'LIVE' : 'SCRUBBED';
-  chip.title = isLive ? 'Clock is at wall-clock now' : 'Live layers paused — scrubbed off now';
+  chip.title = isLive ? 'Clock is at wall-clock now' : 'Scrubbed off now — click to snap back to live';
   chip.dataset.state = isLive ? 'live' : 'scrub';
 }