feat: comprehensive UX improvements — messages, analysis, moderation

Fix #1 (CRITICAL): Wire message_analyzed through Redis EventBroadcaster
- DG aiAnalyzer.ts: Add broadcastAnalysisCompleted() helper that publishes
  to both in-memory WS broadcaster AND Redis EventBroadcaster
- DG bootstrap.ts: Pass eventBroadcaster to startPendingAIAnalysisWorker()
- Fixes broken real-time chain so analysis results appear instantly

Fix #2: Collapsible AI Analysis with Rich Formatting
- MessageCard: AI analysis now collapsible with color-coded severity border
  (red/yellow/blue), summary line showing categories + confidence + severity
- Default collapsed for clean, expanded for warn/flagged

Fix #3: Toast Notifications for Flagged Content
- Wrap app in ToastProvider; ModerationAlertListener component listens for
  moderation_alert custom events and shows toast with emoji + details

Fix #4: Discord-style Message Grouping
- MessageFeed: Group consecutive messages from same user within 5 min
- MessageCard: Compact variant hides avatar, reduces padding for non-first

Fix #5: Moderation Action Buttons in UI
- BE: POST /api/messages/:id/moderate endpoint + publishCommand() for Redis
- FE: Delete/Warn buttons on flagged/warned cards with confirmation dialog

Fix #6: Search Results Include Full Data
- BE analysis.service.ts: SELECT all 26 message columns instead of just 11
- Search results now render with full MessageCard including images/analysis

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

services/backend/src/ws/redis-bridge.ts

@@ -27,8 +27,9 @@ const SUBSCRIPTIONS: ChannelMapping[] = [
 ];
 
 let subscriber: Redis | null = null;
+let publisher: Redis | null = null;
 
-function createSubscriber(): Redis {
+function createRedisInstance(): Redis {
   if (config.REDIS_URL) {
     return new Redis(config.REDIS_URL, { keyPrefix: "" });
   }
@@ -39,6 +40,35 @@ function createSubscriber(): Redis {
   });
 }
 
+function createSubscriber(): Redis {
+  return createRedisInstance();
+}
+
+function getPublisher(): Redis {
+  if (!publisher) {
+    publisher = createRedisInstance();
+  }
+  return publisher;
+}
+
+/**
+ * Publish a command to the Discord Gateway via Redis.
+ * The DG's commandHandler listens on "backend:command" channel.
+ */
+export async function publishCommand(
+  payload: Record<string, unknown>,
+): Promise<void> {
+  const pub = getPublisher();
+  const envelope = {
+    type: "command",
+    data: payload,
+    timestamp: Date.now(),
+    source: "backend",
+  };
+  await pub.publish("backend:command", JSON.stringify(envelope));
+  logger.debug({ payload }, "Published command to DG");
+}
+
 function handleSubscriptionMessage(channel: string, message: string): void {
   const mapping = SUBSCRIPTIONS.find((m) => m.channel === channel);
   if (!mapping) {