feat: Add password hash generation scripts

- Add simple hash-password script for quick hash generation
- Add interactive generate-password script with hidden input
- Include password validation and requirements display
- Add npm scripts for easy execution
- Create comprehensive PASSWORD_GENERATION.md guide
- Use existing bcrypt infrastructure with 12 salt rounds

Usage:
  npm run hash-password YourPassword123\!
  npm run generate-password (interactive)

This solves the issue where bcrypt command line tools
don't work properly for generating compatible hashes.

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

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

backend/scripts/hash-password.js

@@ -0,0 +1,23 @@
+const bcrypt = require('bcrypt');
+
+const password = process.argv[2];
+
+if (!password) {
+  console.error('Usage: npm run hash-password <your-password>');
+  console.error('Example: npm run hash-password MySecurePass123!');
+  process.exit(1);
+}
+
+async function hashPassword() {
+  try {
+    const hash = await bcrypt.hash(password, 12);
+    console.log('\n=== Generated Password Hash ===');
+    console.log(`ADMIN_PASSWORD_HASH=${hash}`);
+    console.log('\nCopy the above line to your .env file');
+  } catch (error) {
+    console.error('Error:', error.message);
+    process.exit(1);
+  }
+}
+
+hashPassword();