Add password hash fix utility

- Created fix_password.py to repair corrupted admin password hash
- Addresses Argon2 InvalidHash error in login

fix_password.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+"""
+Fix corrupted admin password hash in config.json
+"""
+
+import json
+from argon2 import PasswordHasher
+import getpass
+
+def fix_admin_password():
+    """Fix the corrupted admin password hash"""
+    
+    print("Current admin password hash appears to be corrupted.")
+    print("Let's generate a new one...")
+    
+    # Get new password
+    password = getpass.getpass("Enter new admin password: ")
+    confirm = getpass.getpass("Confirm password: ")
+    
+    if password != confirm:
+        print("Passwords don't match!")
+        return
+    
+    # Generate new hash
+    ph = PasswordHasher()
+    new_hash = ph.hash(password)
+    
+    # Load current config
+    try:
+        with open('config.json', 'r') as f:
+            config = json.load(f)
+    except Exception as e:
+        print(f"Error reading config.json: {e}")
+        return
+    
+    # Update the password hash
+    if 'admin' not in config:
+        config['admin'] = {}
+    
+    config['admin']['password_hash'] = new_hash
+    
+    # Save config
+    try:
+        with open('config.json', 'w') as f:
+            json.dump(config, f, indent=2)
+        
+        print("\nPassword hash updated successfully!")
+        print(f"New hash: {new_hash}")
+        print("\nRestart the application for changes to take effect.")
+        
+    except Exception as e:
+        print(f"Error saving config.json: {e}")
+
+if __name__ == "__main__":
+    fix_admin_password()