Index: src/services/PrutterService.js
===================================================================
--- src/services/PrutterService.js	(revision 7bc636b391c66ac399c33e54f7173a022c6a3cbd)
+++ src/services/PrutterService.js	(revision 7bc636b391c66ac399c33e54f7173a022c6a3cbd)
@@ -0,0 +1,196 @@
+/**
+ * PrutterService — Real-time Direct Messaging
+ * 
+ * Features:
+ * - Per-conversation (user A ↔ user B)
+ * - Optional site-specific (conversations tied to a community)
+ * - WebSocket real-time notifications
+ * - Message history in SQLite
+ * - Unread message tracking
+ */
+
+import { v4 as uuid } from 'uuid';
+
+class PrutterService {
+  constructor(db) {
+    this.db = db;
+    this.wsConnections = new Map(); // userId → Set<WebSocket>
+  }
+
+  /**
+   * Get or create conversation
+   */
+  getOrCreateConversation(userA, userB, siteId = null) {
+    if (!userA || !userB) throw new Error('Both users required');
+    
+    // Normalize order: always smaller ID first
+    const [u1, u2] = userA < userB ? [userA, userB] : [userB, userA];
+
+    const existing = this.db.prepare(`
+      SELECT * FROM conversations
+      WHERE (user_a_id = ? AND user_b_id = ? AND site_id IS ?)
+      LIMIT 1
+    `).get(u1, u2, siteId);
+
+    if (existing) {
+      return existing;
+    }
+
+    const convId = uuid();
+    this.db.prepare(`
+      INSERT INTO conversations (id, user_a_id, user_b_id, site_id)
+      VALUES (?, ?, ?, ?)
+    `).run(convId, u1, u2, siteId);
+
+    return { id: convId, user_a_id: u1, user_b_id: u2, site_id: siteId };
+  }
+
+  /**
+   * Send message
+   */
+  sendMessage(conversationId, authorId, content) {
+    if (!conversationId || !authorId || !content) {
+      throw new Error('Missing required fields');
+    }
+
+    const msgId = uuid();
+    const now = new Date().toISOString();
+
+    this.db.prepare(`
+      INSERT INTO messages (id, conversation_id, author_id, content, created_at)
+      VALUES (?, ?, ?, ?, ?)
+    `).run(msgId, conversationId, authorId, content, now);
+
+    // Update last_message_at on conversation
+    this.db.prepare(`
+      UPDATE conversations SET last_message_at = ? WHERE id = ?
+    `).run(now, conversationId);
+
+    // Fetch full message for response
+    const message = this.db.prepare(`
+      SELECT m.*, u.username, u.avatar_url
+      FROM messages m
+      JOIN users u ON m.author_id = u.id
+      WHERE m.id = ?
+    `).get(msgId);
+
+    // Notify recipient via WebSocket (if online)
+    const conv = this.db.prepare('SELECT * FROM conversations WHERE id = ?').get(conversationId);
+    const recipientId = conv.user_a_id === authorId ? conv.user_b_id : conv.user_a_id;
+    
+    this.notifyUser(recipientId, {
+      type: 'new_message',
+      conversationId,
+      message
+    });
+
+    return message;
+  }
+
+  /**
+   * Get conversation messages
+   */
+  getMessages(conversationId, limit = 50, offset = 0) {
+    return this.db.prepare(`
+      SELECT m.*, u.username, u.avatar_url
+      FROM messages m
+      JOIN users u ON m.author_id = u.id
+      WHERE m.conversation_id = ?
+      ORDER BY m.created_at DESC
+      LIMIT ? OFFSET ?
+    `).all(conversationId, limit, offset);
+  }
+
+  /**
+   * Get user's conversations (list)
+   */
+  getUserConversations(userId) {
+    return this.db.prepare(`
+      SELECT c.*,
+             CASE 
+               WHEN c.user_a_id = ? THEN u2.id
+               ELSE u1.id
+             END as other_user_id,
+             CASE 
+               WHEN c.user_a_id = ? THEN u2.username
+               ELSE u1.username
+             END as other_username,
+             CASE 
+               WHEN c.user_a_id = ? THEN u2.avatar_url
+               ELSE u1.avatar_url
+             END as other_avatar,
+             (SELECT COUNT(*) FROM messages m 
+              WHERE m.conversation_id = c.id 
+              AND m.author_id != ? 
+              AND m.read_at IS NULL) as unread_count,
+             (SELECT content FROM messages m 
+              WHERE m.conversation_id = c.id 
+              ORDER BY m.created_at DESC LIMIT 1) as last_message_preview
+      FROM conversations c
+      JOIN users u1 ON c.user_a_id = u1.id
+      JOIN users u2 ON c.user_b_id = u2.id
+      WHERE c.user_a_id = ? OR c.user_b_id = ?
+      ORDER BY c.last_message_at DESC
+    `).all(userId, userId, userId, userId, userId, userId);
+  }
+
+  /**
+   * Mark conversation messages as read
+   */
+  markAsRead(conversationId, userId) {
+    const now = new Date().toISOString();
+    this.db.prepare(`
+      UPDATE messages
+      SET read_at = ?
+      WHERE conversation_id = ? AND author_id != ? AND read_at IS NULL
+    `).run(now, conversationId, userId);
+  }
+
+  /**
+   * WebSocket connection management
+   */
+  addConnection(userId, ws) {
+    if (!this.wsConnections.has(userId)) {
+      this.wsConnections.set(userId, new Set());
+    }
+    this.wsConnections.get(userId).add(ws);
+  }
+
+  removeConnection(userId, ws) {
+    const conns = this.wsConnections.get(userId);
+    if (conns) {
+      conns.delete(ws);
+      if (conns.size === 0) {
+        this.wsConnections.delete(userId);
+      }
+    }
+  }
+
+  /**
+   * Notify user via WebSocket (if online)
+   */
+  notifyUser(userId, message) {
+    const conns = this.wsConnections.get(userId);
+    if (!conns) return;
+
+    const data = JSON.stringify(message);
+    for (const ws of conns) {
+      if (ws.readyState === 1) { // OPEN
+        ws.send(data);
+      }
+    }
+  }
+
+  /**
+   * Broadcast to all users in conversation (except sender)
+   */
+  broadcastToConversation(conversationId, senderUserId, message) {
+    const conv = this.db.prepare('SELECT * FROM conversations WHERE id = ?').get(conversationId);
+    if (!conv) return;
+
+    const otherUserId = conv.user_a_id === senderUserId ? conv.user_b_id : conv.user_a_id;
+    this.notifyUser(otherUserId, message);
+  }
+}
+
+export default PrutterService;