feat(ui): show repo count in contribution graph summaries

Add "in N repositories" to both the year and all-time graph summary
lines. Year graph counts repos with overlapping activity; all-time
graph uses total project count. OG image includes repo count too.

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

ui/src/components/ContributionGraph.tsx

@@ -2,7 +2,7 @@ import { useMemo } from 'react';
 import { useQuery } from '@tanstack/react-query';
 import { useNavigate } from 'react-router-dom';
 
-import { fetchDailyCounts, fetchSources } from '../api/client';
+import { fetchDailyCounts, fetchProjects, fetchSources } from '../api/client';
 
 const CELL_SIZE = 12;
 const GAP = 3;
@@ -37,6 +37,23 @@ export function ContributionGraph() {
     staleTime: 5 * 60_000,
   });
 
+  const projectsQ = useQuery({
+    queryKey: ['projects'],
+    queryFn: fetchProjects,
+    staleTime: 60_000,
+  });
+
+  const repoCount = useMemo(() => {
+    if (!projectsQ.data) return 0;
+    const fromMs = from.getTime();
+    const toMs = to.getTime();
+    return projectsQ.data.filter((p) => {
+      const first = p.first_activity ? new Date(p.first_activity).getTime() : Infinity;
+      const last = p.last_activity ? new Date(p.last_activity).getTime() : 0;
+      return last >= fromMs && first <= toMs;
+    }).length;
+  }, [projectsQ.data]);
+
   const navigate = useNavigate();
 
   const { weeks, monthMarkers, thresholds, totalCount } = useMemo(() => {
@@ -89,6 +106,7 @@ export function ContributionGraph() {
     <div className="contribution-graph mb-3">
       <p style={{ fontSize: '0.8rem', opacity: 0.6 }}>
         {totalCount} contributions in the last year
+        {repoCount > 0 && ` in ${repoCount} repositories`}
       </p>
       <div>
         <svg viewBox={`0 0 ${svgWidth} ${svgHeight}`} width="100%" className="d-block">
@@ -155,6 +173,13 @@ export function AllTimeGraph() {
     return dates.length > 0 ? new Date(Math.min(...dates.map((d) => d.getTime()))) : null;
   }, [sourcesQ.data]);
 
+  const projectsQ = useQuery({
+    queryKey: ['projects'],
+    queryFn: fetchProjects,
+    staleTime: 60_000,
+  });
+  const repoCount = projectsQ.data?.length ?? 0;
+
   const to = new Date();
   const from = earliest ?? new Date(to.getFullYear() - 5, 0, 1);
   const fromStr = fmt(from);
@@ -227,6 +252,7 @@ export function AllTimeGraph() {
     <div className="contribution-graph mb-4">
       <p style={{ fontSize: '0.8rem', opacity: 0.6 }}>
         {totalCount} contributions since {fmt(from)}
+        {repoCount > 0 && ` in ${repoCount} repositories`}
       </p>
       <div>
         <svg viewBox={`0 0 ${svgWidth} ${svgHeight}`} width="100%" className="d-block">