fix(minimax): harden OAuth dashboard and runtime

Handle MiniMax OAuth expiry values consistently across CLI and dashboard
flows, fix CLI status/add behavior, and force pooled OAuth runtime
requests through Anthropic Messages.

- web_server._minimax_poller: parse expired_in via the shared resolver
  so unix-ms absolute timestamps stop landing as TTL seconds and crashing
  with 'year 583911 is out of range' when a user connects MiniMax OAuth
  from the dashboard.
- auth._minimax_oauth_login / _refresh_minimax_oauth_state: same fix on
  the CLI login + refresh paths.
- auth.get_auth_status: dispatch minimax-oauth to its dedicated status
  function instead of falling through.
- auth_commands.auth_add_command: 'hermes auth add minimax-oauth' now
  starts the device-code login flow and persists a pool entry with the
  access + refresh tokens, instead of requiring credentials to already
  exist.
- runtime_provider._resolve_runtime_from_pool_entry: pin pooled
  minimax-oauth credentials to anthropic_messages so a stale
  model.api_mode: chat_completions can't send requests to
  /anthropic/chat/completions and trigger MiniMax nginx 404s.

Co-authored-by: Cursor <cursoragent@cursor.com>

hermes_cli/runtime_provider.py

@@ -205,6 +205,14 @@ def _resolve_runtime_from_pool_entry(
     elif provider == "google-gemini-cli":
         api_mode = "chat_completions"
         base_url = base_url or "cloudcode-pa://google"
+    elif provider == "minimax-oauth":
+        # MiniMax OAuth tokens are valid only against the Anthropic Messages
+        # compatible endpoint. Do not honor stale model.api_mode values from a
+        # prior OpenAI-compatible provider, or the client will hit
+        # /chat/completions under /anthropic and receive a bare nginx 404.
+        api_mode = "anthropic_messages"
+        pconfig = PROVIDER_REGISTRY.get(provider)
+        base_url = base_url or (pconfig.inference_base_url if pconfig else "")
     elif provider == "anthropic":
         api_mode = "anthropic_messages"
         cfg_provider = str(model_cfg.get("provider") or "").strip().lower()