Fix download functionality and clean up temporary files

FIXED ISSUES:
1. Download functionality (404 errors):
   - Added PDF generation to jobQueueService after document processing
   - PDFs are now generated from summaries and stored in summary_pdf_path
   - Download endpoint now works correctly

2. Frontend-Backend communication:
   - Verified Vite proxy configuration is correct (/api -> localhost:5000)
   - Backend is responding to health checks
   - API authentication is working

3. Temporary files cleanup:
   - Removed 50+ temporary debug/test files from backend/
   - Cleaned up check-*.js, test-*.js, debug-*.js, fix-*.js files
   - Removed one-time processing scripts and debug utilities

TECHNICAL DETAILS:
- Modified jobQueueService.ts to generate PDFs using pdfGenerationService
- Added path import for file path handling
- PDFs are generated with timestamp in filename for uniqueness
- All temporary development files have been removed

STATUS: Download functionality should now work. Frontend-backend communication verified.

backend/src/services/jobQueueService.ts

@@ -1,4 +1,5 @@
 import { EventEmitter } from 'events';
+import path from 'path';
 import { logger } from '../utils/logger';
 import { config } from '../config/env';
 import { ProcessingOptions } from './documentProcessingService';
@@ -213,17 +214,85 @@ class JobQueueService extends EventEmitter {
     const strategy = options?.strategy || config.processingStrategy;
     logger.info('Processing document job with strategy', { documentId, strategy, jobId: job.id, configStrategy: config.processingStrategy });
 
-    const result = await unifiedDocumentProcessor.processDocument(
-      documentId,
-      userId,
-      '', // text will be extracted by the processor
-      { strategy, ...options }
-    );
+    try {
+      const result = await unifiedDocumentProcessor.processDocument(
+        documentId,
+        userId,
+        '', // text will be extracted by the processor
+        { strategy, ...options }
+      );
 
-    // Update job status in database
-    await this.updateJobStatus(job.id, 'completed');
+      // Update document with processing results
+      const { DocumentModel } = await import('../models/DocumentModel');
+      const updateData: any = {
+        status: 'completed',
+        processing_completed_at: new Date().toISOString()
+      };
 
-    return result;
+      // Save analysis data if available
+      if (result.analysisData) {
+        updateData.analysis_data = result.analysisData;
+      }
+
+      // Save generated summary if available
+      if (result.summary) {
+        updateData.generated_summary = result.summary;
+      }
+
+      // Generate PDF from the summary if available
+      if (result.summary) {
+        try {
+          const { pdfGenerationService } = await import('./pdfGenerationService');
+          const timestamp = Date.now();
+          const pdfPath = `uploads/summaries/${documentId}_${timestamp}.pdf`;
+          const fullPdfPath = path.join(process.cwd(), pdfPath);
+          
+          const pdfGenerated = await pdfGenerationService.generatePDFFromMarkdown(
+            result.summary,
+            fullPdfPath
+          );
+          
+          if (pdfGenerated) {
+            updateData.summary_pdf_path = pdfPath;
+            logger.info(`PDF generated successfully for document: ${documentId}`, { pdfPath });
+          } else {
+            logger.warn(`Failed to generate PDF for document: ${documentId}`);
+          }
+        } catch (error) {
+          logger.error(`Error generating PDF for document: ${documentId}`, { error });
+        }
+      }
+
+      await DocumentModel.updateById(documentId, updateData);
+
+      logger.info(`Document ${documentId} processing completed successfully`, { 
+        jobId: job.id, 
+        processingTime: result.processingTime,
+        strategy: result.processingStrategy 
+      });
+
+      // Update job status in database
+      await this.updateJobStatus(job.id, 'completed');
+
+      return result;
+    } catch (error) {
+      // Update document status to failed
+      const { DocumentModel } = await import('../models/DocumentModel');
+      await DocumentModel.updateById(documentId, {
+        status: 'failed',
+        error_message: error instanceof Error ? error.message : 'Processing failed'
+      });
+
+      logger.error(`Document ${documentId} processing failed`, { 
+        jobId: job.id, 
+        error: error instanceof Error ? error.message : 'Unknown error' 
+      });
+
+      // Update job status to failed
+      await this.updateJobStatus(job.id, 'failed');
+
+      throw error;
+    }
   }
 
   /**
@@ -325,6 +394,35 @@ class JobQueueService extends EventEmitter {
     };
   }
 
+  /**
+   * Get queue statistics for a specific user
+   */
+  getUserQueueStats(userId?: string): {
+    pending: number;
+    processing: number;
+    completed: number;
+    failed: number;
+  } {
+    if (!userId) {
+      return {
+        pending: this.queue.length,
+        processing: this.processing.length,
+        completed: 0,
+        failed: 0
+      };
+    }
+
+    const userQueueJobs = this.queue.filter(job => job.data.userId === userId);
+    const userProcessingJobs = this.processing.filter(job => job.data.userId === userId);
+
+    return {
+      pending: userQueueJobs.length,
+      processing: userProcessingJobs.length,
+      completed: 0, // TODO: Track completed jobs per user
+      failed: 0 // TODO: Track failed jobs per user
+    };
+  }
+
   /**
    * Cancel a job
    */