feat: add "Reset for Smoke Test" button in admin settings

Truncates sources, curriculum, content, quiz banks/results/cache, topics
and relations in dependency order so AI-generated state can be wiped
between smoke runs without leaving dangling references. Handbook sync
state is cleared by default (otherwise re-sync is a no-op); user
progress and leaderboard are opt-in. Team members, settings, and LLM
telemetry are preserved.

UI lives in Admin → Settings → Danger Zone and requires typing RESET
before the button enables. Per-collection deletion counts are reported.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/lib/db.js

@@ -338,6 +338,56 @@ export async function getRecentLlmCalls(limit = 100) {
   }
 }
 
+// ── Reset for Smoke Testing ──────────────────────────────────────────────────
+
+/**
+ * Truncate the collections that hold AI-generated and progress data.
+ *
+ * Order matters: rows that reference `topics.id` (relations, content,
+ * quiz_banks) are deleted before topics themselves so we never leave
+ * dangling references mid-wipe.
+ *
+ * `team_members`, `settings`, and `llm_calls` are intentionally preserved.
+ *
+ * @param {{ includeHandbookState?: boolean, includeProgress?: boolean }} [opts]
+ * @returns {Promise<Array<{collection: string, deleted: number, error?: string}>>}
+ */
+export async function resetForSmokeTest({
+  includeHandbookState = true,
+  includeProgress = false,
+} = {}) {
+  const collections = [
+    'relations',
+    'content',
+    'quiz_banks',
+    'quiz_results',
+    'quiz_cache',
+    'curriculum',
+    'sources',
+    'topics',
+  ];
+  if (includeHandbookState) collections.push('handbook_sync_state');
+  if (includeProgress) collections.push('learn_progress', 'leaderboard');
+
+  const results = [];
+  for (const name of collections) {
+    try {
+      const rows = await pb.collection(name).getFullList({ fields: 'id', requestKey: null });
+      // Sequential deletes — bulk delete-many isn't in the JS SDK and parallel
+      // deletes on the same collection sometimes 409 in PocketBase.
+      let deleted = 0;
+      for (const r of rows) {
+        await pb.collection(name).delete(r.id, { requestKey: null });
+        deleted++;
+      }
+      results.push({ collection: name, deleted });
+    } catch (err) {
+      results.push({ collection: name, deleted: 0, error: err?.message || String(err) });
+    }
+  }
+  return results;
+}
+
 // ── Handbook Sync State ───────────────────────────────────────────────────────
 
 export async function getHandbookSyncStates() {