style(tui): simplify runtime header controls

tui/src/runtime-controls.ts

@@ -309,10 +309,7 @@ export class RuntimeControls {
   }
 
   private render(): void {
-    const runtime = this.modelPreset !== "default"
-      ? [this.modelPreset, this.model].filter(Boolean).join("     ")
-      : this.model
-    this.modelText.content = `     ${runtime} ▾`
+    this.modelText.content = `${this.modelPreset} ▾`
     const access = this.scope.access_mode === "full" ? "full access" : "workspace access"
     this.accessText.content = `     ${access} ▾`
     this.renderColors()