Fixes#22832.
## Root cause
`hermes_cli/web_server.py:start_oauth_login` dispatched OAuth flows by
the catalog's `flow` field rather than provider id:
if catalog_entry["flow"] == "pkce":
return _start_anthropic_pkce()
The catalog had two `flow: "pkce"` entries — `anthropic` and
`minimax-oauth` — so clicking "Login" on MiniMax in the dashboard's
Keys tab unconditionally launched the Anthropic/Claude PKCE flow.
## Fix
Three changes in `hermes_cli/web_server.py`:
1. Catalog entry for `minimax-oauth` changed from `flow: "pkce"` to
`flow: "device_code"`. From a UX perspective MiniMax is a
verification-URI + user-code flow (open URL, enter code, backend
polls) — same shape as Nous's device-code flow. The PKCE bit
(verifier + challenge from `_minimax_pkce_pair`) is a security
extension that doesn't change the operator experience; the existing
dashboard modal already renders `device_code` correctly for this UX.
2. New MiniMax branch in `_start_device_code_flow`, mirroring the
existing Nous branch but calling MiniMax-specific helpers
(`_minimax_request_user_code`, `_minimax_pkce_pair`). Stashes
verifier + state in the session for the poller to consume. Handles
the overloaded `expired_in` field (could be unix-ms timestamp OR
seconds-from-now duration) the same way `_minimax_poll_token` does.
3. New `_minimax_poller` background thread mirroring `_nous_poller`.
Calls `_minimax_poll_token` → on success builds the same
`auth_state` dict the CLI flow (`_minimax_oauth_login`) builds, and
persists via `_minimax_save_auth_state` so the dashboard path leaves
the system in the same state as `hermes auth add minimax-oauth`.
Plus a dispatcher tightening to prevent regression: the `pkce` branch
now requires `provider_id == "anthropic"`, so any future PKCE provider
added without a proper start function gets a clean
`400 Unsupported flow` rather than silently launching Anthropic OAuth.
## Test
New `tests/hermes_cli/test_web_oauth_dispatch.py`:
- Regression test asserting MiniMax start does NOT return claude.ai
- Sanity test that Anthropic PKCE still works after the dispatcher
tightening
- Forward-looking test: a hypothetical pkce-flagged provider without
an explicit branch is rejected cleanly rather than misrouted
## Limitations
- The dashboard MiniMax path defaults to `region="global"`. CN-region
operators can still use the CLI flow which supports `--region cn`.
Adding a region toggle to the dashboard UI is a follow-up.
