fix(model): require confirmation for expensive model selections

Rebased onto current main and re-ported across the restructured
surfaces: model flows now thread confirm_provider/base_url/api_key
through hermes_cli/model_setup_flows.py, the Discord picker lives in
plugins/platforms/discord/adapter.py, and the web dashboard picker
applies chat-mode switches via config.set so the expensive-model
confirmation can ride the response.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

hermes_cli/auth.py

@@ -6175,6 +6175,40 @@ def _reset_config_provider() -> Path:
     return config_path
 
 
+def _confirm_expensive_model_selection(
+    model_id: str,
+    *,
+    provider: str = "",
+    base_url: str = "",
+    api_key: str = "",
+) -> bool:
+    """Prompt before saving a model whose known pricing exceeds guardrails."""
+    try:
+        from hermes_cli.model_cost_guard import expensive_model_warning
+
+        warning = expensive_model_warning(
+            model_id,
+            provider=provider,
+            base_url=base_url,
+            api_key=api_key,
+        )
+    except Exception:
+        warning = None
+    if warning is None:
+        return True
+
+    print()
+    print("=" * 72)
+    print(warning.message)
+    print("=" * 72)
+    try:
+        response = input("Switch anyway? [y/N]: ").strip().lower()
+    except (KeyboardInterrupt, EOFError):
+        print()
+        return False
+    return response in {"y", "yes"}
+
+
 def _prompt_model_selection(
     model_ids: List[str],
     current_model: str = "",
@@ -6182,6 +6216,9 @@ def _prompt_model_selection(
     unavailable_models: Optional[List[str]] = None,
     portal_url: str = "",
     unavailable_message: str = "",
+    confirm_provider: str = "",
+    confirm_base_url: str = "",
+    confirm_api_key: str = "",
 ) -> Optional[str]:
     """Interactive model selection. Puts current_model first with a marker. Returns chosen model ID or None.
 
@@ -6195,6 +6232,18 @@ def _prompt_model_selection(
 
     _unavailable = unavailable_models or []
 
+    def _confirmed_selection(mid: str) -> Optional[str]:
+        if not mid:
+            return None
+        if confirm_provider and not _confirm_expensive_model_selection(
+            mid,
+            provider=confirm_provider,
+            base_url=confirm_base_url,
+            api_key=confirm_api_key,
+        ):
+            return None
+        return mid
+
     # Reorder: current model first, then the rest (deduplicated)
     ordered = []
     if current_model and current_model in model_ids:
@@ -6310,13 +6359,13 @@ def _prompt_model_selection(
             return None
         print()
         if idx < len(ordered):
-            return ordered[idx]
+            return _confirmed_selection(ordered[idx])
         elif idx == len(ordered):
             try:
                 custom = input("Enter model name: ").strip()
             except (EOFError, KeyboardInterrupt):
                 return None
-            return custom if custom else None
+            return _confirmed_selection(custom) if custom else None
         return None
     except (ImportError, NotImplementedError, OSError, subprocess.SubprocessError):
         pass
@@ -6348,10 +6397,10 @@ def _prompt_model_selection(
                 return None
             idx = int(choice)
             if 1 <= idx <= n:
-                return ordered[idx - 1]
+                return _confirmed_selection(ordered[idx - 1])
             elif idx == n + 1:
                 custom = input("Enter model name: ").strip()
-                return custom if custom else None
+                return _confirmed_selection(custom) if custom else None
             elif idx == n + 2:
                 return None
             print(f"Please enter 1-{n + 2}")
@@ -7730,6 +7779,9 @@ def _login_nous(args, pconfig: ProviderConfig) -> None:
                     unavailable_models=unavailable_models,
                     portal_url=_portal,
                     unavailable_message=unavailable_message,
+                    confirm_provider="nous",
+                    confirm_base_url=inference_base_url,
+                    confirm_api_key=runtime_key,
                 )
             elif unavailable_models:
                 _url = (_portal or DEFAULT_NOUS_PORTAL_URL).rstrip("/")