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/modules/messages/messages.routes.ts

@@ -91,5 +91,72 @@ export function createMessagesRouter(): Router {
     }),
   );
 
+  // POST /api/messages/:id/moderate — Trigger moderation action via DG
+  router.post(
+    "/messages/:id/moderate",
+    asyncHandler(async (req: Request, res: Response) => {
+      const id = req.params.id;
+      if (!id) {
+        res.status(400).json({ error: "MISSING_ID" });
+        return;
+      }
+
+      const { actionType, reason } = (req.body ?? {}) as {
+        actionType?: string;
+        reason?: string;
+      };
+
+      const allowedActions = [
+        "delete_message",
+        "warn_user",
+        "kick_user",
+        "ban_user",
+        "mute_user",
+      ];
+
+      if (!actionType || !allowedActions.includes(actionType)) {
+        res.status(400).json({
+          error: "INVALID_ACTION",
+          message: `actionType must be one of: ${allowedActions.join(", ")}`,
+        });
+        return;
+      }
+
+      // Fetch the message to get guild/user context
+      const pool = getPool();
+      const { rows } = await pool.query(
+        `SELECT id, guild_id, channel_id, thread_id, user_id, content
+         FROM messages WHERE id = $1`,
+        [id],
+      );
+
+      if (rows.length === 0) {
+        res.status(404).json({ error: "MESSAGE_NOT_FOUND" });
+        return;
+      }
+
+      const msg = rows[0] as Record<string, unknown>;
+
+      // Publish command to DG via Redis
+      const { publishCommand } = await import("../../ws/redis-bridge.js");
+      await publishCommand({
+        id: crypto.randomUUID(),
+        type: "moderation:action",
+        payload: {
+          messageId: id,
+          guildId: String(msg.guild_id ?? ""),
+          channelId: (msg.thread_id as string) || String(msg.channel_id ?? ""),
+          userId: String(msg.user_id ?? ""),
+          actionType,
+          reason: reason ?? "Manual moderation from dashboard",
+          requestedAt: Date.now(),
+        },
+      });
+
+      logger.info({ id, actionType, reason }, "Moderation action dispatched");
+      res.json({ ok: true, actionType, messageId: id });
+    }),
+  );
+
   return router;
 }