Closes
https://linear.app/codercom/issue/AIGOV-284/add-group-budgets-table-and-crud-api
## Summary
Adds the `group_ai_budgets` table and the following endpoints:
- `GET /api/v2/groups/{group}/ai/budget`
- `PUT /api/v2/groups/{group}/ai/budget`
- `DELETE /api/v2/groups/{group}/ai/budget`
Each group may have at most one budget row. If no row exists, no budget
is enforced.
### Feature gate
Added `RequireFeatureMW(FeatureAIBridge)` on the `/ai/budget` sub-route.
## RBAC
Authorization reuses `rbac.ResourceGroup` with the existing
`.InOrganization(...).WithID(...)` scoping model.
The `dbauthz` wrappers load the parent `groups` row and authorize
against it.
No new resource type is introduced. As a result, anyone with
`group:update` permissions (Owner, OrgAdmin, or UserAdmin within the
organization) can manage AI budgets for that group.
## Read access for group members
`database.Group.RBACObject()` grants `policy.ActionRead` to all members
of the group through the group ACL:
```go
func (g Group) RBACObject() rbac.Object {
return rbac.ResourceGroup.WithID(g.ID).
InOrg(g.OrganizationID).
// Group members can read the group.
WithGroupACL(map[string][]policy.Action{
g.ID.String(): {
policy.ActionRead,
},
})
}
```
Because the `GET` endpoint authorizes against the same loaded `Group`
object, any group member can call:
```text
GET /api/v2/groups/{group}/ai/budget
```
`PUT` and `DELETE` remain admin-only. The group ACL grants only
`ActionRead`, so write operations continue to require role-based
`group:update` permissions.
## Alternative considered
A dedicated `rbac.ResourceGroupAiBudget` resource would allow budget
management to be separated from general group administration.
We decided not to add that complexity for now.
Yevhenii Shcherbina