fix: normalize anthropic model ids

src/agents/model-selection.ts

@@ -27,6 +27,15 @@ export function normalizeProviderId(provider: string): string {
   return normalized;
 }
 
+function normalizeAnthropicModelId(model: string): string {
+  const trimmed = model.trim();
+  if (!trimmed) return trimmed;
+  const lower = trimmed.toLowerCase();
+  if (lower === "opus-4.5") return "claude-opus-4-5";
+  if (lower === "sonnet-4.5") return "claude-sonnet-4-5";
+  return trimmed;
+}
+
 export function parseModelRef(
   raw: string,
   defaultProvider: string,
@@ -35,13 +44,18 @@ export function parseModelRef(
   if (!trimmed) return null;
   const slash = trimmed.indexOf("/");
   if (slash === -1) {
-    return { provider: normalizeProviderId(defaultProvider), model: trimmed };
+    const provider = normalizeProviderId(defaultProvider);
+    const model =
+      provider === "anthropic" ? normalizeAnthropicModelId(trimmed) : trimmed;
+    return { provider, model };
   }
   const providerRaw = trimmed.slice(0, slash).trim();
   const provider = normalizeProviderId(providerRaw);
   const model = trimmed.slice(slash + 1).trim();
   if (!provider || !model) return null;
-  return { provider, model };
+  const normalizedModel =
+    provider === "anthropic" ? normalizeAnthropicModelId(model) : model;
+  return { provider, model: normalizedModel };
 }
 
 export function buildModelAliasIndex(params: {