chore: add user details to aibridge interception list endpoint (#20397)

- Adds FK from `aibridge_interceptions.initiator_id` to `users.id`
- This is enforced by deleting any rows that don't have any users. Since
this is an experimental feature AND coder never deletes user rows I
think this is acceptable.
- Adds `name` as a property on `codersdk.MinimalUser`
- This matches the `visible_users` view in the database. I'm unsure why
`name` wasn't already included given that `username` is.
- Adds a new `initiator` field to `codersdk.AIBridgeInterception` which
contains `codersdk.MinimalUser` (ID, username, name, avatar URL)
- Removes `initiator_id` from `codersdk.AIBridgeInterception`
    - Should be fine since we're still in early access

coderd/database/dump.sql

@@ -3511,6 +3511,9 @@ COMMENT ON TRIGGER workspace_agent_name_unique_trigger ON workspace_agents IS 'U
 the uniqueness requirement. A trigger allows us to enforce uniqueness going
 forward without requiring a migration to clean up historical data.';
 
+ALTER TABLE ONLY aibridge_interceptions
+    ADD CONSTRAINT aibridge_interceptions_initiator_id_fkey FOREIGN KEY (initiator_id) REFERENCES users(id);
+
 ALTER TABLE ONLY api_keys
     ADD CONSTRAINT api_keys_user_id_uuid_fkey FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE;