Remove weekly report functionality

- Delete backend/routes/weeklyReports.js
- Delete backend/migrations/add_weekly_reports_table.js
- Delete backend/scripts/split_cve_report.py
- Delete backend/helpers/excelProcessor.js
- Delete frontend/src/components/WeeklyReportModal.js
- Remove import, state, button, and modal from App.js
- Remove route registration and require from server.js
- Drop weekly_reports table from SQLite database

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/helpers/excelProcessor.js

@@ -1,93 +0,0 @@
-const { spawn } = require('child_process');
-const path = require('path');
-const fs = require('fs');
-
-/**
- * Process vulnerability report Excel file by splitting CVE IDs into separate rows
- * @param {string} inputPath - Path to original Excel file
- * @param {string} outputPath - Path for processed Excel file
- * @returns {Promise<{original_rows: number, processed_rows: number, output_path: string}>}
- */
-function processVulnerabilityReport(inputPath, outputPath) {
-  return new Promise((resolve, reject) => {
-    const scriptPath = path.join(__dirname, '..', 'scripts', 'split_cve_report.py');
-
-    // Verify script exists
-    if (!fs.existsSync(scriptPath)) {
-      return reject(new Error(`Python script not found: ${scriptPath}`));
-    }
-
-    // Verify input file exists
-    if (!fs.existsSync(inputPath)) {
-      return reject(new Error(`Input file not found: ${inputPath}`));
-    }
-
-    const python = spawn('python3', [scriptPath, inputPath, outputPath]);
-
-    let stdout = '';
-    let stderr = '';
-    let timedOut = false;
-
-    // 30 second timeout
-    const timeout = setTimeout(() => {
-      timedOut = true;
-      python.kill();
-      reject(new Error('Processing timed out. File may be too large or corrupted.'));
-    }, 30000);
-
-    python.stdout.on('data', (data) => {
-      stdout += data.toString();
-    });
-
-    python.stderr.on('data', (data) => {
-      stderr += data.toString();
-    });
-
-    python.on('close', (code) => {
-      clearTimeout(timeout);
-
-      if (timedOut) return;
-
-      if (code !== 0) {
-        // Parse Python error messages
-        if (stderr.includes('Sheet') && stderr.includes('not found')) {
-          return reject(new Error('Invalid Excel file. Expected "Vulnerabilities" sheet with "CVE ID" column.'));
-        }
-        if (stderr.includes('pandas') || stderr.includes('openpyxl')) {
-          return reject(new Error('Python dependencies missing. Run: pip3 install pandas openpyxl'));
-        }
-        return reject(new Error(`Python script failed: ${stderr || 'Unknown error'}`));
-      }
-
-      // Parse output for row counts
-      const originalMatch = stdout.match(/Original rows:\s*(\d+)/);
-      const newMatch = stdout.match(/New rows:\s*(\d+)/);
-
-      if (!originalMatch || !newMatch) {
-        return reject(new Error('Failed to parse row counts from Python output'));
-      }
-
-      // Verify output file was created
-      if (!fs.existsSync(outputPath)) {
-        return reject(new Error('Processed file was not created'));
-      }
-
-      resolve({
-        original_rows: parseInt(originalMatch[1]),
-        processed_rows: parseInt(newMatch[1]),
-        output_path: outputPath
-      });
-    });
-
-    python.on('error', (err) => {
-      clearTimeout(timeout);
-      if (err.code === 'ENOENT') {
-        reject(new Error('Python 3 is required but not found. Please install Python.'));
-      } else {
-        reject(err);
-      }
-    });
-  });
-}
-
-module.exports = { processVulnerabilityReport };