Enable Granular Access Control via Multiple Scoped API Keys

As a developer integrating Reusely with third-party tools, I want to be able to generate unique API keys with limited scopes (permissions), So that I can limit the security blast radius if a specific key is exposed or a third-party service is compromised.

(The equivalent to User Permissions but for API Access)

Acceptance Criteria / Desired Functionality:

• User can create more than one Public API Key or Secret Key.

• User can name/label keys for easy identification.

• User can assign specific scopes to a key (e.g., Read Only, Write Only, Full Access).

• User can revoke a specific key without rotating the global account secret.

Impact: High. The current single-key implementation blocks us from using Reusely in secure environments where the Principle of Least Privilege is a requirement.