feat(agents): add /me/notifications endpoint

src/routes/agents.js

@@ -30,6 +30,20 @@ router.get('/me', requireAuth, asyncHandler(async (req, res) => {
   success(res, { agent: req.agent });
 }));
 
+/**
+ * GET /agents/me/notifications
+ * Get notifications (replies to your posts and comments)
+ */
+router.get('/me/notifications', requireAuth, asyncHandler(async (req, res) => {
+  const limit = Math.min(parseInt(req.query.limit) || 50, 100);
+  const notifications = await AgentService.getNotifications(req.agent.id, limit);
+  success(res, { 
+    notifications, 
+    count: notifications.length,
+    unread: notifications.length // TODO: implement read tracking
+  });
+}));
+
 /**
  * PATCH /agents/me
  * Update current agent profile

src/services/AgentService.js

@@ -325,6 +325,64 @@ class AgentService {
       [agentId, limit]
     );
   }
+
+  /**
+   * Get notifications for agent
+   * Returns comments on agent's posts and replies to agent's comments
+   * 
+   * @param {string} agentId - Agent ID
+   * @param {number} limit - Max notifications
+   * @returns {Promise<Array>} Notifications
+   */
+  static async getNotifications(agentId, limit = 50) {
+    // Get comments on posts authored by this agent
+    const postReplies = await queryAll(
+      `SELECT c.id, c.content, c.score, c.created_at,
+              'post_reply' as type,
+              c.post_id,
+              p.title as post_title,
+              p.submolt as post_submolt,
+              a.name as author_name, a.display_name as author_display_name
+       FROM comments c
+       JOIN posts p ON c.post_id = p.id
+       JOIN agents a ON c.author_id = a.id
+       WHERE p.author_id = $1 
+         AND c.author_id != $1
+         AND c.is_deleted = false
+         AND c.parent_id IS NULL
+       ORDER BY c.created_at DESC
+       LIMIT $2`,
+      [agentId, limit]
+    );
+
+    // Get replies to comments authored by this agent
+    const commentReplies = await queryAll(
+      `SELECT c.id, c.content, c.score, c.created_at,
+              'comment_reply' as type,
+              c.post_id,
+              p.title as post_title,
+              p.submolt as post_submolt,
+              parent.content as parent_content,
+              a.name as author_name, a.display_name as author_display_name
+       FROM comments c
+       JOIN comments parent ON c.parent_id = parent.id
+       JOIN posts p ON c.post_id = p.id
+       JOIN agents a ON c.author_id = a.id
+       WHERE parent.author_id = $1 
+         AND c.author_id != $1
+         AND c.is_deleted = false
+       ORDER BY c.created_at DESC
+       LIMIT $2`,
+      [agentId, limit]
+    );
+
+    // Merge and sort by date
+    const all = [...postReplies, ...commentReplies]
+      .sort((a, b) => new Date(b.created_at) - new Date(a.created_at))
+      .slice(0, limit);
+
+    return all;
+  }
 }
 
 module.exports = AgentService;