update daily aggregation to use hourly intervals

components/views/index.templ

@@ -63,6 +63,7 @@ templ Index(info BuildInfo) {
 							<li>Daily summaries aggregate the hourly snapshots for the day; monthly summaries aggregate daily summaries for the month (or hourly snapshots if configured).</li>
 							<li>Snapshots are registered in `snapshot_registry` so regeneration via `/api/snapshots/aggregate` can locate the correct tables (fallback scanning is also supported).</li>
 							<li>Reports (XLSX with totals/charts) are generated automatically after hourly, daily, and monthly jobs and written to a reports directory.</li>
+							<li>Hourly totals are interval-based: each row represents [HH:00, HH+1:00) and uses the first snapshot at or after the hour end (including cross-day snapshots) to prorate VM presence.</li>
 						</ul>
 					</div>
 					<div class="web2-card">