fix: align Nous Portal model slugs with OpenRouter naming (#3253)

Nous Portal now passes through OpenRouter model names and routes from
there. Update the static fallback model list and auxiliary client default
to use OpenRouter-format slugs (provider/model) instead of bare names.

- _PROVIDER_MODELS['nous']: full OpenRouter catalog
- _NOUS_MODEL: google/gemini-3-flash-preview (was gemini-3-flash)
- Updated 4 test assertions for the new default model name

hermes_cli/models.py

@@ -53,12 +53,29 @@ OPENROUTER_MODELS: list[tuple[str, str]] = [
 
 _PROVIDER_MODELS: dict[str, list[str]] = {
     "nous": [
-        "claude-opus-4-6",
-        "claude-sonnet-4-6",
-        "gpt-5.4",
-        "gemini-3-flash",
-        "gemini-3.0-pro-preview",
-        "deepseek-v3.2",
+        "anthropic/claude-opus-4.6",
+        "anthropic/claude-sonnet-4.5",
+        "anthropic/claude-haiku-4.5",
+        "openai/gpt-5.4",
+        "openai/gpt-5.4-mini",
+        "xiaomi/mimo-v2-pro",
+        "openai/gpt-5.3-codex",
+        "google/gemini-3-pro-preview",
+        "google/gemini-3-flash-preview",
+        "qwen/qwen3.5-plus-02-15",
+        "qwen/qwen3.5-35b-a3b",
+        "stepfun/step-3.5-flash",
+        "minimax/minimax-m2.7",
+        "minimax/minimax-m2.5",
+        "z-ai/glm-5",
+        "z-ai/glm-5-turbo",
+        "moonshotai/kimi-k2.5",
+        "x-ai/grok-4.20-beta",
+        "nvidia/nemotron-3-super-120b-a12b",
+        "nvidia/nemotron-3-super-120b-a12b:free",
+        "arcee-ai/trinity-large-preview:free",
+        "openai/gpt-5.4-pro",
+        "openai/gpt-5.4-nano",
     ],
     "openai-codex": [
         "gpt-5.3-codex",