Fix issues #49 and #50: Migration errors and missing worker manager

- Fix #49: Add column existence checks to migration 011_add_user_upload_settings.js
  to prevent "column already exists" errors during deployment
- Fix #50: Create missing workerManager.js file that starts background services
  (file watcher and expiration checker) for native installations

backend/migrations/legacy/011_add_user_upload_settings.js

@@ -1,23 +1,56 @@
 exports.up = async function(knex) {
-  // Add user upload settings to events table
+  // Add user upload settings to events table (check if columns exist first)
+  const hasAllowUserUploads = await knex.schema.hasColumn('events', 'allow_user_uploads');
+  if (!hasAllowUserUploads) {
+    console.log('Adding allow_user_uploads column to events table...');
     await knex.schema.alterTable('events', function(table) {
       table.boolean('allow_user_uploads').defaultTo(false);
+    });
+  } else {
+    console.log('Column allow_user_uploads already exists in events table, skipping...');
+  }
+
+  const hasUploadCategoryId = await knex.schema.hasColumn('events', 'upload_category_id');
+  if (!hasUploadCategoryId) {
+    console.log('Adding upload_category_id column to events table...');
+    await knex.schema.alterTable('events', function(table) {
       table.integer('upload_category_id').references('id').inTable('photo_categories').onDelete('SET NULL');
     });
+  } else {
+    console.log('Column upload_category_id already exists in events table, skipping...');
+  }
 
   // Add uploaded_by field to photos table to track who uploaded
+  const hasUploadedBy = await knex.schema.hasColumn('photos', 'uploaded_by');
+  if (!hasUploadedBy) {
+    console.log('Adding uploaded_by column to photos table...');
     await knex.schema.alterTable('photos', function(table) {
       table.string('uploaded_by').defaultTo('admin'); // 'admin' or guest identifier
     });
+  } else {
+    console.log('Column uploaded_by already exists in photos table, skipping...');
+  }
 };
 
 exports.down = async function(knex) {
+  const hasAllowUserUploads = await knex.schema.hasColumn('events', 'allow_user_uploads');
+  if (hasAllowUserUploads) {
     await knex.schema.alterTable('events', function(table) {
       table.dropColumn('allow_user_uploads');
+    });
+  }
+
+  const hasUploadCategoryId = await knex.schema.hasColumn('events', 'upload_category_id');
+  if (hasUploadCategoryId) {
+    await knex.schema.alterTable('events', function(table) {
       table.dropColumn('upload_category_id');
     });
+  }
 
+  const hasUploadedBy = await knex.schema.hasColumn('photos', 'uploaded_by');
+  if (hasUploadedBy) {
     await knex.schema.alterTable('photos', function(table) {
       table.dropColumn('uploaded_by');
     });
+  }
 };

backend/src/services/workerManager.js

@@ -0,0 +1,72 @@
+/**
+ * Worker Manager - Background service for PicPeak
+ *
+ * This service runs as a separate process to handle:
+ * - File watching for new photos
+ * - Expiration checking for events
+ * - Other background tasks
+ */
+
+const path = require('path');
+const logger = require('../utils/logger');
+
+// Load environment variables
+require('dotenv').config({ path: path.join(__dirname, '../../.env') });
+
+// Import services
+const { startFileWatcher } = require('./fileWatcher');
+const { startExpirationChecker } = require('./expirationChecker');
+
+let isShuttingDown = false;
+
+async function startWorkers() {
+  logger.info('Starting PicPeak background workers...');
+
+  try {
+    // Start file watcher for automatic photo processing
+    startFileWatcher();
+    logger.info('File watcher started successfully');
+
+    // Start expiration checker for event lifecycle management
+    startExpirationChecker();
+    logger.info('Expiration checker started successfully');
+
+    logger.info('All background workers started successfully');
+  } catch (error) {
+    logger.error('Failed to start background workers:', error);
+    process.exit(1);
+  }
+}
+
+function handleShutdown(signal) {
+  if (isShuttingDown) {
+    logger.info('Shutdown already in progress...');
+    return;
+  }
+
+  isShuttingDown = true;
+  logger.info(`Received ${signal}. Shutting down gracefully...`);
+
+  // Give time for cleanup
+  setTimeout(() => {
+    logger.info('Worker manager shutdown complete');
+    process.exit(0);
+  }, 1000);
+}
+
+// Handle shutdown signals
+process.on('SIGTERM', () => handleShutdown('SIGTERM'));
+process.on('SIGINT', () => handleShutdown('SIGINT'));
+
+// Handle uncaught errors
+process.on('uncaughtException', (error) => {
+  logger.error('Uncaught exception in worker manager:', error);
+  process.exit(1);
+});
+
+process.on('unhandledRejection', (reason, promise) => {
+  logger.error('Unhandled rejection in worker manager:', reason);
+});
+
+// Start workers
+startWorkers();