fix: break moderation infinite re-review loop by adding 'flagged' status

When AI flags an event, transition status to 'flagged' instead of
leaving it as 'pending'. This prevents processPending() from picking
up the same flagged events every 30-second poll cycle and burning
AI tokens indefinitely.

- Add 'flagged' to QUEUE_STATUSES enum in schema
- Set status='flagged' in autoReview() when AI flags an event
- Include flagged count in admin stats endpoint
- Add index on relay_event_queue.status for efficient queries

Fixes #27

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

artifacts/api-server/src/lib/moderation.ts

@@ -134,7 +134,7 @@ export class ModerationService {
   /**
    * Review a single pending event with Claude.
    * Returns "approve" (event is injected into strfry + status → auto_approved)
-   * or "flag" (status stays pending — admin must decide).
+   * or "flag" (status → flagged — admin must decide).
    */
   async autoReview(eventId: string): Promise<ModerationDecision> {
     const rows = await db
@@ -176,10 +176,10 @@ export class ModerationService {
     if (result.decision === "approve") {
       await this.decide(eventId, "auto_approved", result.reason, "timmy_ai");
     } else {
-      // Update reason but leave status as "pending" for admin
+      // Transition to "flagged" so processPending() won't re-review this event
       await db
         .update(relayEventQueue)
-        .set({ reviewReason: result.reason, reviewedBy: "timmy_ai" })
+        .set({ status: "flagged", reviewReason: result.reason, reviewedBy: "timmy_ai" })
         .where(eq(relayEventQueue.eventId, eventId));
 
       logger.info("moderation: event flagged for admin review", {

artifacts/api-server/src/routes/admin-relay.ts

@@ -106,6 +106,7 @@ router.get("/admin/relay/stats", requireAdmin, async (_req: Request, res: Respon
 
   res.json({
     pending: statusMap["pending"] ?? 0,
+    flagged: statusMap["flagged"] ?? 0,
     approved: statusMap["approved"] ?? 0,
     autoApproved: statusMap["auto_approved"] ?? 0,
     rejected: statusMap["rejected"] ?? 0,