feat: Generate secure random password for Administrator

[asaura08]

This pull request improves the security and user experience of the create command in frappe_manager/commands.py by changing how the administrator password is handled. If the user does not provide an admin_pass, the system will now automatically generate a secure random password instead of defaulting to a weak hardcoded password.

Password handling improvements:

• Changed the admin_pass parameter in the create command to be optional; if not provided, a secure random password is generated using the secrets and string modules. [1] [2]
• Added imports for the secrets and string modules to support secure password generation

[Copilot]

Pull request overview

This pull request enhances security by replacing the hardcoded default administrator password "admin" with an automatically generated secure random password when users don't provide one explicitly.

Key changes:

• Modified the admin_pass parameter to be optional (Optional[str] with None default)
• Added automatic generation of 16-character random passwords using the secrets module when no password is provided
• Updated help text to inform users about the auto-generation feature

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

The generated password should include special characters for stronger security. Currently, it only uses letters and digits. Consider using string.ascii_letters + string.digits + string.punctuation for the alphabet to create more secure passwords that meet common password complexity requirements.

Suggested change

	alphabet = string.ascii_letters + string.digits
	alphabet = string.ascii_letters + string.digits + string.punctuation