Show the first-recorded date on the All history button tooltip

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

app/public/dashboard-ui.js

@@ -578,6 +578,11 @@ async function refreshData() {
     ]);
     DAILY = daily; RECENT = recent;
     LATEST = RECENT[RECENT.length - 1] || null;
+    const allBtn = document.querySelector('.range-btn[data-range="all"]');
+    if (allBtn && DAILY[0]) {
+      const first = new Date(dayMs(DAILY[0].d)).toLocaleDateString('en-US', { month: 'short', day: 'numeric', year: 'numeric', timeZone: 'UTC' });
+      allBtn.title = `Everything recorded since ${first}`;
+    }
     if (LATEST?.tz) TZ = LATEST.tz;
     if (!LOC) {
       const loc = await getJSON('/api/dashboard/location').catch(() => null);