This pull-request implements a simple filtering logic so that we're able
to pick which model the user actually used when logs were sent to AI
Bridge.
- Add `GET /aibridge/models` API endpoint that returns distinct model
names from AI Bridge interceptions, with pagination and search support
- New `ListAIBridgeModels` SQL query using case-sensitive prefix
matching (`LIKE model || '%'`) to allow B-tree index usage
- Hand-written `ListAuthorizedAIBridgeModels` in `modelqueries.go` for
RBAC authorization filter injection
- `AIBridgeModels` search query parser in searchquery/search.go
(defaults bare terms to the `model` field)
- dbauthz wrappers, dbmetrics, and dbmock implementations for the new
query
<img width="292" height="185" alt="image"
src="https://github.com/user-attachments/assets/134771df-2d26-4c54-acc4-27f58128b351"
/>
Jake Howell
d2787df442