Licensing: Remove entitlement for AI Bridge from Premium license

[!NOTE]
This issue is a part of our larger AI Governance Add-On: PRD. See the GitHub Project for all related issues.

With AI Bridge going out of Beta in Feb 3, we are moving it out of our Premium license as an add-on license to be added.

Requirements

• Soft warning: For deployments with AI Bridge enabled, the Auditor and Owner role should see a warning banner in the Coder UI and logs that reads like the following

  <AI Bridge/Entitlement Name> has reached General Availability and your Coder deployment is not entitled to run this feature. Contact your account team for information around getting a license with AI Bridge.

  The feature should still be usable in v2.30, although a future version of Coder may include hard enforcement. The behavior with Auditor and Owner role aims to match existing entitlement and overage warnings. If my understanding is not accurate, let's fall back to the existing RBAC around entitlement warnings.

• Existing Premium licenses and future licenses generated should not include the AI Bridge entitlement, as an add-on license will be created