Closes
https://linear.app/codercom/issue/AIGOV-287/add-effective-group-resolution
Implements the effective AI budget resolution from the AI Governance
cost-controls RFC: for a given user, a `user_ai_budget_overrides` row
wins if present, otherwise the deployment budget policy (`highest`)
picks the largest group budget across the user's groups, ties broken
alphabetically.
For now, I keep the logic under `coderd/aibridge/budget`, but that may
change during the implementation of budget enforcement.
Yevhenii Shcherbina
1cada0649c