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>

tests/hermes_cli/test_runtime_provider_resolution.py

@@ -2285,3 +2285,39 @@ def test_minimax_oauth_runtime_uses_inference_base_url(monkeypatch):
     resolved = rp.resolve_runtime_provider(requested="minimax-oauth")
 
     assert MINIMAX_OAUTH_CN_INFERENCE.rstrip("/") in resolved["base_url"]
+
+
+def test_minimax_oauth_pool_forces_anthropic_messages_despite_stale_config(monkeypatch):
+    """A pooled MiniMax OAuth token must not inherit stale chat_completions config."""
+
+    class _Entry:
+        access_token = "oauth-token"
+        source = "manual:minimax_oauth"
+        base_url = "https://api.minimax.io/anthropic"
+
+    class _Pool:
+        def has_credentials(self):
+            return True
+
+        def select(self):
+            return _Entry()
+
+    monkeypatch.setattr(rp, "resolve_provider", lambda *a, **k: "minimax-oauth")
+    monkeypatch.setattr(
+        rp,
+        "_get_model_config",
+        lambda: {
+            "provider": "minimax-oauth",
+            "default": "MiniMax-M2.7",
+            "api_mode": "chat_completions",
+        },
+    )
+    monkeypatch.setattr(rp, "load_pool", lambda provider: _Pool())
+    monkeypatch.setattr(rp, "_resolve_named_custom_runtime", lambda **k: None)
+    monkeypatch.setattr(rp, "_resolve_explicit_runtime", lambda **k: None)
+
+    resolved = rp.resolve_runtime_provider(requested="minimax-oauth")
+
+    assert resolved["provider"] == "minimax-oauth"
+    assert resolved["api_mode"] == "anthropic_messages"
+    assert resolved["base_url"] == "https://api.minimax.io/anthropic"