feat(models): remote model catalog manifest for OpenRouter + Nous Portal (#16033)

OpenRouter and Nous Portal curated picker lists now resolve via a JSON
manifest served by the docs site, falling back to the in-repo snapshot
when unreachable. Lets us update model lists without shipping a release.

Live URL: https://hermes-agent.nousresearch.com/docs/api/model-catalog.json
(source at website/static/api/model-catalog.json; auto-deploys via the
existing deploy-site.yml GitHub Pages pipeline on every merge to main).

Schema (v1) carries id + optional description + free-form metadata at
manifest, provider, and model levels. Pricing and context length stay
live-fetched via existing machinery (/v1/models endpoints, models.dev).

Config (new model_catalog section, default enabled):
  model_catalog.url       master manifest URL
  model_catalog.ttl_hours disk cache TTL (default 24h)
  model_catalog.providers.<name>.url   optional per-provider override

Fetch pipeline: in-process cache -> disk cache (fresh < TTL) -> HTTP
fetch -> disk-cache-on-failure fallback -> in-repo snapshot as last
resort. Never raises to callers; at worst returns the bundled list.

Changes:
- website/static/api/model-catalog.json    initial manifest (35 OR + 31 Nous)
- scripts/build_model_catalog.py           regenerator from in-repo lists
- hermes_cli/model_catalog.py              fetch + validate + cache module
- hermes_cli/models.py                     fetch_openrouter_models() +
                                           new get_curated_nous_model_ids()
- hermes_cli/main.py, hermes_cli/auth.py   Nous flows use the helper
- hermes_cli/config.py                     model_catalog defaults
- website/docs/reference/model-catalog.md  + sidebars.ts
- tests/hermes_cli/test_model_catalog.py   21 tests (validation, fetch
                                           success/failure, accessors,
                                           disabled, overrides, integration)

hermes_cli/models.py

@@ -876,7 +876,16 @@ def fetch_openrouter_models(
     if _openrouter_catalog_cache is not None and not force_refresh:
         return list(_openrouter_catalog_cache)
 
-    fallback = list(OPENROUTER_MODELS)
+    # Prefer the remotely-hosted catalog manifest; fall back to the in-repo
+    # snapshot when the manifest is unreachable. Both are curated lists that
+    # drive the picker; the OpenRouter live /v1/models filter (tool support,
+    # free pricing) is applied on top either way.
+    try:
+        from hermes_cli.model_catalog import get_curated_openrouter_models
+        remote = get_curated_openrouter_models()
+    except Exception:
+        remote = None
+    fallback = list(remote) if remote else list(OPENROUTER_MODELS)
     preferred_ids = [mid for mid, _ in fallback]
 
     try:
@@ -929,6 +938,24 @@ def model_ids(*, force_refresh: bool = False) -> list[str]:
     return [mid for mid, _ in fetch_openrouter_models(force_refresh=force_refresh)]
 
 
+def get_curated_nous_model_ids() -> list[str]:
+    """Return the curated Nous Portal model-id list.
+
+    Prefers the remotely-hosted catalog manifest (published under
+    ``website/static/api/model-catalog.json``); falls back to the in-repo
+    snapshot in ``_PROVIDER_MODELS["nous"]`` when the manifest is
+    unreachable. Always returns a list (never None).
+    """
+    try:
+        from hermes_cli.model_catalog import get_curated_nous_models
+        remote = get_curated_nous_models()
+    except Exception:
+        remote = None
+    if remote:
+        return list(remote)
+    return list(_PROVIDER_MODELS.get("nous", []))
+
+
 def _ai_gateway_model_is_free(pricing: Any) -> bool:
     """Return True if an AI Gateway model has $0 input AND output pricing."""
     if not isinstance(pricing, dict):