TUI: benchmark running command viewport relayout

Co-Authored-By: Oz <oz-agent@warp.dev>

Author: harryalbert

crates/warp_tui/benches/transcript_bench.rs

@@ -23,9 +23,14 @@ fn benchmark_running_agent_command(criterion: &mut Criterion) {
         let mut benchmark =
             TranscriptBenchmark::new(TranscriptDataset::RunningAgentCommand { rows }, 120, 50);
         group.bench_with_input(
-            BenchmarkId::new("retained_unchanged_frame", rows),
+            BenchmarkId::new("viewport_relayout_unchanged_frame", rows),
             &rows,
-            |b, _| b.iter(|| black_box(benchmark.present())),
+            |b, _| {
+                b.iter(|| {
+                    benchmark.invalidate_viewport();
+                    black_box(benchmark.present())
+                })
+            },
         );
     }
     group.finish();

crates/warp_tui/src/benchmark_support.rs

@@ -282,6 +282,18 @@ impl TranscriptBenchmark {
         })
     }
 
+    /// Re-renders the transcript viewport without dirtying retained agent blocks.
+    pub fn invalidate_viewport(&mut self) {
+        let invalidation = WindowInvalidation {
+            updated: EntityIdSet::from_iter([self.root.id()]),
+            ..Default::default()
+        };
+        self.app.read(|ctx| {
+            self.presenter
+                .invalidate(&invalidation, ctx, self.root.window_id(ctx));
+        });
+    }
+
     /// Re-renders the root and long agent block before the next frame.
     pub fn invalidate_all(&mut self) {
         let mut updated = EntityIdSet::from_iter([self.root.id()]);