feat: Add production-ready utilities and performance improvements

Security & Data Integrity:
- Centralized transaction helper with deadlock retry (exponential backoff)
- SafeQueryBuilder for safe parameterized queries
- Zod-based input validation middleware
- Audit logging to Outline's events table

Performance:
- Cursor-based pagination for large datasets
- Pool monitoring with configurable alerts
- Database index migrations for optimal query performance

Changes:
- Refactored bulk-operations, desk-sync, export-import to use centralized transaction helper
- Added 7 new utility modules (audit, monitoring, pagination, query-builder, transaction, validation)
- Created migrations/001_indexes.sql with 40+ recommended indexes

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/tools/export-import.ts

@@ -4,27 +4,9 @@
  * @author Descomplicar® | @link descomplicar.pt | @copyright 2026
  */
 
-import { Pool, PoolClient } from 'pg';
 import { BaseTool, ToolResponse } from '../types/tools.js';
 import { isValidUUID, sanitizeInput } from '../utils/security.js';
-
-/**
- * Execute operations within a transaction
- */
-async function withTransaction<T>(pool: Pool, callback: (client: PoolClient) => Promise<T>): Promise<T> {
-  const client = await pool.connect();
-  try {
-    await client.query('BEGIN');
-    const result = await callback(client);
-    await client.query('COMMIT');
-    return result;
-  } catch (error) {
-    await client.query('ROLLBACK');
-    throw error;
-  } finally {
-    client.release();
-  }
-}
+import { withTransaction } from '../utils/transaction.js';
 
 interface ExportCollectionArgs {
   collection_id: string;