## Problem
`codex cloud` always instantiated `AuthManager` with `File` mode,
ignoring the user's actual `cli_auth_credentials_store` setting. This
caused users with `cli_auth_credentials_store = "keyring"` (or `"auto"`)
to see "Not signed in" errors even when they had valid credentials
stored in the system keyring.
## Root cause
The code called `Config::load_from_base_config_with_overrides()` with an
empty `ConfigToml::default()`, which always returned `File` as the
default store mode instead of loading the actual user configuration.
## Solution
- **Added `util::load_cli_auth_manager()` helper**
Properly loads user config via
`load_config_as_toml_with_cli_overrides()` and extracts the
`cli_auth_credentials_store` setting before creating `AuthManager`.
- **Updated callers**
- `init_backend()` - used when starting cloud tasks UI
- `build_chatgpt_headers()` - used for API requests
## Testing
- ✅ `just fmt`
- ✅ `just fix -p codex-cloud-tasks`
- ✅ `cargo test -p codex-cloud-tasks`
## Files changed
- `codex-rs/cloud-tasks/src/lib.rs`
- `codex-rs/cloud-tasks/src/util.rs`
## Verification
Users with keyring-based auth can now run `codex cloud` successfully
without "Not signed in" errors.
---------
Co-authored-by: Eric Traut <etraut@openai.com>
Co-authored-by: celia-oai <celia@openai.com>
This PR is a follow-up to #5591. It allows users to choose which auth
storage mode they want by using the new
`cli_auth_credentials_store_mode` config.
