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/routes/protectedImages.js

@@ -1,6 +1,7 @@
 const express = require('express');
 const path = require('path');
 const { db } = require('../database/db');
+const { formatBoolean } = require('../utils/dbCompat');
 const { verifyGalleryAccess } = require('../middleware/gallery');
 const watermarkService = require('../services/watermarkService');
 const { getStoragePath } = require('../config/storage');
@@ -141,7 +142,7 @@ router.get('/:slug/photo/:photoId/signed/:token', async (req, res) => {
     // Get event
     const event = await db('events')
       .where({ slug })
-      .where('is_active', true)
+      .where('is_active', formatBoolean(true))
       .first();
     
     if (!event) {