feat(ui): show private activity count on timeline when no public events

When viewing a date range with zero public activities, the status line
now shows the count of private contributions (derived from daily counts
which include private repos). Helps explain gaps in the public timeline.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/pages/TimelineHome.tsx

@@ -5,7 +5,7 @@ import Col from 'react-bootstrap/Col';
 import Row from 'react-bootstrap/Row';
 import { VerticalTimeline } from 'react-vertical-timeline-component';
 
-import { fetchEvents, fetchSources, type Source } from '../api/client';
+import { fetchDailyCounts, fetchEvents, fetchSources, type Source } from '../api/client';
 import { Filters } from '../components/Filters';
 import { TimelineEntry } from '../components/TimelineEntry';
 
@@ -82,6 +82,19 @@ export function TimelineHome() {
 
   const events = eventsQ.data ?? [];
 
+  const fromStr = new Date(rangeValue[0]).toISOString().slice(0, 10);
+  const toStr = new Date(rangeValue[1]).toISOString().slice(0, 10);
+  const dailyQ = useQuery({
+    queryKey: ['daily-counts', fromStr, toStr],
+    queryFn: () => fetchDailyCounts(fromStr, toStr),
+    staleTime: 5 * 60_000,
+  });
+  const totalCount = useMemo(
+    () => (dailyQ.data ?? []).reduce((sum, d) => sum + d.count, 0),
+    [dailyQ.data],
+  );
+  const privateCount = totalCount - events.length;
+
   return (
     <>
       <Filters
@@ -105,7 +118,7 @@ export function TimelineHome() {
               ? 'loading…'
               : eventsQ.isError
                 ? `error: ${(eventsQ.error as Error).message}`
-                : `showing ${events.length} ${events.length === 1 ? 'activity' : 'activities'}`}
+                : `showing ${events.length} public ${events.length === 1 ? 'activity' : 'activities'}${privateCount > 0 ? `, ${privateCount} private` : ''}`}
           </p>
           <VerticalTimeline>
             {events.map((item) => (