feat: add Nous Portal API key provider (#644)

Add support for using Nous Portal via a direct API key, mirroring
how OpenRouter and other API-key providers work. This gives users a
simpler alternative to the OAuth device-code flow when they already
have a Nous API key.

Changes:
- Add 'nous-api' to PROVIDER_REGISTRY as an api_key provider
  pointing to https://inference-api.nousresearch.com/v1
- Add NOUS_API_KEY and NOUS_BASE_URL to OPTIONAL_ENV_VARS
- Add NOUS_API_BASE_URL / NOUS_API_CHAT_URL to hermes_constants
- Add 'Nous Portal API key' as first option in setup wizard
- Add provider aliases (nous_api, nousapi, nous-portal-api)
- Add test for nous-api runtime provider resolution

Closes #644

hermes_cli/auth.py

@@ -108,6 +108,14 @@ PROVIDER_REGISTRY: Dict[str, ProviderConfig] = {
         auth_type="oauth_external",
         inference_base_url=DEFAULT_CODEX_BASE_URL,
     ),
+    "nous-api": ProviderConfig(
+        id="nous-api",
+        name="Nous Portal (API Key)",
+        auth_type="api_key",
+        inference_base_url="https://inference-api.nousresearch.com/v1",
+        api_key_env_vars=("NOUS_API_KEY",),
+        base_url_env_var="NOUS_BASE_URL",
+    ),
     "zai": ProviderConfig(
         id="zai",
         name="Z.AI / GLM",
@@ -513,6 +521,7 @@ def resolve_provider(
 
     # Normalize provider aliases
     _PROVIDER_ALIASES = {
+        "nous_api": "nous-api", "nousapi": "nous-api", "nous-portal-api": "nous-api",
         "glm": "zai", "z-ai": "zai", "z.ai": "zai", "zhipu": "zai",
         "kimi": "kimi-coding", "moonshot": "kimi-coding",
         "minimax-china": "minimax-cn", "minimax_cn": "minimax-cn",