Enhance security with password hashing and fix documentation/dependencies

[google-labs-jules]

This pull request addresses several issues to improve the security and maintainability of the CandyPanel project.

Changes:

1. Security Enhancement:

   • Implemented password hashing for the admin user in Backend/core.py. Previously, passwords were stored in plaintext.
   • Added a migration mechanism in the _admin_login function to automatically upgrade existing plaintext passwords to hashed versions upon the next successful login.
   • Added werkzeug to Backend/requirements.txt for secure password hashing.

2. Documentation & Setup:

   • Corrected readme.md to accurately describe the backend stack as Flask (previously incorrectly mentioned FastAPI).
   • Updated backend installation instructions to use pip install -r requirements.txt.
   • Created Backend/requirements.txt with all necessary dependencies (flask, flask_cors, pyrogram, werkzeug, etc.).

3. Frontend:

   • Ensured frontend builds correctly by updating dependencies.

These changes significantly improve the security posture of the application and ensure that the installation instructions are accurate and reproducible.

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PR created automatically by Jules for task 10877279448616426985 started by @AmiRCandy

[google-labs-jules]

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