Secure Credential Endpoints with JWT Authentication

[nee1k]

Our current credential endpoints (/get_hf_credentials, /get_github_credentials, /get_ndp_credentials) expose sensitive tokens directly. To secure these endpoints, we need to implement JWT-based authentication so that only authorized users can access the credentials.

Requirements:

• Implement a JWT validation decorator (e.g., @token_required) that checks for a valid token in the Authorization header.
• Protect the credential endpoints with this decorator.
• Use os.getenv() to retrieve the credentials from the server's environment.
• Ensure requests with missing or invalid tokens return a 401 error.

Acceptance:
Only valid JWTs allow access to the endpoints; otherwise, return 401 Unauthorized.

[nee1k]

Registering a user would also help in securely sharing the repository credentials.