fix: comprehensive boolean compatibility for PostgreSQL and SQLite

- Add formatBoolean() usage to all boolean database queries
- Fix 36 boolean comparisons across 18 backend files
- Ensure compatibility between SQLite (0/1) and PostgreSQL (true/false)
- Update all WHERE clauses and UPDATE operations with boolean values

This completes the database compatibility fixes for production deployment.
All boolean operations now work correctly with both database systems.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

backend/src/utils/authSecurity.js

@@ -4,6 +4,7 @@
  */
 
 const { db } = require('../database/db');
+const { formatBoolean } = require('./dbCompat');
 const logger = require('./logger');
 
 // Configuration constants
@@ -59,7 +60,7 @@ async function trackSuccessfulLogin(identifier, ipAddress, userAgent) {
     const cutoffTime = new Date(Date.now() - ATTEMPT_WINDOW);
     await db('login_attempts')
       .where('identifier', identifier)
-      .where('success', false)
+      .where('success', formatBoolean(false))
       .where('attempt_time', '<', cutoffTime.toISOString())
       .delete();
   } catch (error) {
@@ -79,7 +80,7 @@ async function checkAccountLockout(identifier) {
     // Get recent failed attempts
     const failedAttempts = await db('login_attempts')
       .where('identifier', identifier)
-      .where('success', false)
+      .where('success', formatBoolean(false))
       .where('attempt_time', '>=', recentWindow.toISOString())
       .orderBy('attempt_time', 'desc')
       .limit(MAX_LOGIN_ATTEMPTS);