## Problem
Non-admin users of the Agents (chat) feature send `model_config_id:
"00000000-0000-0000-0000-000000000000"` (nil UUID) when creating chats,
because the `GET /api/experimental/chats/model-configs` endpoint
requires `policy.ActionRead` on `rbac.ResourceDeploymentConfig`, which
is only granted to admins.
The flow:
1. `AgentsPage.tsx` calls `useQuery(chatModelConfigs())` → hits
`listChatModelConfigs`
2. Non-admin users get a **403 Forbidden** response
3. `chatModelConfigsQuery.data` is `undefined`, so the
`modelConfigIDByModelID` map is empty
4. `handleCreateChat` falls back to `nilUUID` for `model_config_id`
5. The backend rejects the nil UUID: `"Invalid model config ID."`
## Fix
Changed `listChatModelConfigs` to allow all authenticated users to read
model configs:
- **Admin users** continue to see all configs (including disabled ones)
for management via `GetChatModelConfigs`
- **Non-admin users** now see only enabled configs via
`GetEnabledChatModelConfigs` with a system context, which is sufficient
for using the chat feature
This follows the same pattern as `listChatModels`, which already uses
`dbauthz.AsSystemRestricted(ctx)` to allow all authenticated users to
see available models.
Write endpoints (create/update/delete) retain their existing
`ResourceDeploymentConfig` authorization.
## Testing
- Updated `TestListChatModelConfigs/ForbiddenForOrganizationMember` →
`SuccessForOrganizationMember` to verify non-admin users can list
enabled model configs
- All existing chat tests continue to pass