fix(model-resolution): normalize model format and remove dead config flag

src/shared/model-resolution-pipeline.ts

@@ -34,7 +34,6 @@ export type ModelResolutionResult = {
   variant?: string
   attempted?: string[]
   reason?: string
-  explicitUserConfig?: boolean
 }
 
 
@@ -56,7 +55,7 @@ export function resolveModelPipeline(
   const normalizedUserModel = normalizeModel(intent?.userModel)
   if (normalizedUserModel) {
     log("Model resolved via config override", { model: normalizedUserModel })
-    return { model: normalizedUserModel, provenance: "override", explicitUserConfig: true }
+    return { model: normalizedUserModel, provenance: "override" }
   }
 
   const normalizedCategoryDefault = normalizeModel(intent?.categoryDefaultModel)