Compact successful command activity in the TUI (#38921)

## What changed

- Group consecutive successful agent and unified-exec startup commands into a compact `Ran N commands` entry while preserving their full transcript.
- Flush command groups at interaction boundaries, after failures, and after 32 completed commands. Keep manual shell commands and failed or declined commands visible.
- Apply the same grouping rules when replaying thread history without duplicating command starts or disturbing unrelated active commands.

## Testing

- Add TUI coverage for live and replayed grouping, transcript preservation, failures, overlapping commands, group limits, and interaction boundaries.

GitOrigin-RevId: d6602a20201644012fcff3d6cecf4690024383a9

codex-rs/tui/src/chatwidget/replay.rs

@@ -147,6 +147,32 @@ impl ChatWidget {
                 status: codex_app_server_protocol::CommandExecutionStatus::InProgress,
                 ..
             } => self.on_command_execution_started(item),
+            item @ ThreadItem::CommandExecution {
+                source: ExecCommandSource::Agent | ExecCommandSource::UnifiedExecStartup,
+                status:
+                    codex_app_server_protocol::CommandExecutionStatus::Completed
+                    | codex_app_server_protocol::CommandExecutionStatus::Failed,
+                ..
+            } if from_replay => {
+                if matches!(
+                    &item,
+                    ThreadItem::CommandExecution {
+                        status: codex_app_server_protocol::CommandExecutionStatus::Failed,
+                        ..
+                    }
+                ) {
+                    self.flush_completed_command_activity();
+                }
+                if !self.transcript.active_cell.as_ref().is_some_and(|cell| {
+                    cell.as_any()
+                        .downcast_ref::<ExecCell>()
+                        .is_some_and(ExecCell::is_active)
+                        || cell.as_any().is::<McpToolCallCell>()
+                }) {
+                    self.handle_command_execution_started_now(item.clone());
+                }
+                self.handle_command_execution_completed_now(item);
+            }
             item @ ThreadItem::CommandExecution { .. } => self.on_command_execution_completed(item),
             ThreadItem::FileChange {
                 status: codex_app_server_protocol::PatchApplyStatus::InProgress,