feat: add GraphControls component and useGraphData hook for knowledge graph management

src/lib/db.js

@@ -53,7 +53,15 @@ export async function upsertTopic(topic) {
 // ── Relations ────────────────────────────────────────────────────────────────
 
 export async function getRelations() {
-  return pb.collection('relations').getFullList();
+  const records = await pb.collection('relations').getFullList();
+  // Always return plain string IDs for source/target.
+  // PocketBase can return populated objects when relation fields are expanded;
+  // normalising here means callers never need the `r.source?.id || r.source` dance.
+  return records.map(r => ({
+    ...r,
+    source: typeof r.source === 'object' && r.source !== null ? r.source.id : r.source,
+    target: typeof r.target === 'object' && r.target !== null ? r.target.id : r.target,
+  }));
 }
 
 export async function saveRelations(relations) {
@@ -234,6 +242,17 @@ export async function getLeaderboard() {
   return entries.sort((a, b) => (b.points || 0) - (a.points || 0));
 }
 
+/**
+ * Fetch every test_results record across all users, newest first.
+ * Used by the Contributions page to build per-user heatmaps, streaks,
+ * perfect-score counts, and the recent-activity feed in a single query.
+ */
+export async function getAllTestResults() {
+  try {
+    return await pb.collection('test_results').getFullList({ sort: '-created' });
+  } catch { return []; }
+}
+
 export async function upsertLeaderboardEntry(userId, name, pointsDelta, testsCompletedDelta = 0) {
   try {
     const r = await pb.collection('leaderboard').getFirstListItem(`user_id="${userId}"`);