feat(tui): enhance model selection and improve UI components

- Added tests for handling key events in model selector, including Enter and ArrowDown functionality.
- Updated TUI layout to include a new header, activity bar, and improved status bar with spinner and uptime.
- Refactored transcript rendering to support markdown and improved message display.
- Introduced overlays for model selection, help, and editor with appropriate rendering logic.
- Implemented smoke tests for various TUI states to ensure UI integrity and functionality.

src/interfaces/tui/run.ts

@@ -58,6 +58,25 @@ function makeTurnRunner(runtime: WiredRuntime, state: AppStateRest): TurnRunner
   };
 }
 
+/** Append an entry to the bounded live-activity breadcrumb. */
+function addActivity(
+  state: AppStateRest,
+  entry: { label: string; detail?: string; kind: "tool" | "agent" | "error" },
+): void {
+  const activity = state.misc.activity;
+  // Dedupe consecutive repeats of the same tool so `read read read` collapses.
+  const last = activity[activity.length - 1];
+  const key = `${entry.label}:${entry.kind}`;
+  if (last && `${last.label}:${last.kind}` === key && last.detail === entry.detail) {
+    last.count = (last.count ?? 1) + 1;
+  } else {
+    activity.push({ ...entry, count: 1 });
+  }
+  // Keep the breadcrumb tight (max 12 entries).
+  while (activity.length > 12) activity.shift();
+  state.dirty = true;
+}
+
 /** Route one live `TurnEvent` into TUI state (transcript, status bar, toasts). */
 function handleEvent(state: AppStateRest, ev: TurnEvent): void {
   switch (ev.kind) {
@@ -74,38 +93,34 @@ function handleEvent(state: AppStateRest, ev: TurnEvent): void {
       );
       break;
     case "tool_result":
-      pushTranscript(
-        state,
-        makeChatMessage(
-          Roles.Tool,
-          `→ ${ev.tool_name}${ev.is_error ? " (error)" : ""}`,
-        ),
-      );
+      // A tool result is a breadcrumb, not a full transcript entry — keep the
+      // transcript clean and fold the tool name into the live activity bar.
+      addActivity(state, {
+        label: ev.tool_name,
+        detail: ev.is_error ? "error" : undefined,
+        kind: ev.is_error ? "error" : "tool",
+      });
       break;
     case "usage":
       state.lastUsage = { tokensIn: ev.tokens_in, tokensOut: ev.tokens_out };
       state.dirty = true;
       break;
     case "agent_progress":
-      pushTranscript(
-        state,
-        makeChatMessage(
-          Roles.Tool,
-          `[${ev.progress.agent_name}] ${ev.progress.status}${ev.progress.error ? ` — ${ev.progress.error}` : ev.progress.current_tool ? ` · ${ev.progress.current_tool}` : ""}`,
-        ),
-      );
+      addActivity(state, {
+        label: ev.progress.agent_name,
+        detail: ev.progress.error ?? ev.progress.current_tool ?? undefined,
+        kind: ev.progress.error ? "error" : "agent",
+      });
       break;
     case "workflow_agent_update":
-      pushTranscript(
-        state,
-        makeChatMessage(
-          Roles.Tool,
-          `[${ev.agent_name}] ${ev.status}${ev.error ? ` — ${ev.error}` : ""}`,
-        ),
-      );
+      addActivity(state, {
+        label: ev.agent_name,
+        detail: ev.error ?? undefined,
+        kind: ev.error ? "error" : "agent",
+      });
       break;
     case "error":
-      pushTranscript(state, makeChatMessage(Roles.System, `error: ${ev.message}`));
+      addActivity(state, { label: "error", detail: ev.message, kind: "error" });
       toastError(state, `Turn error: ${ev.message}`);
       break;
     case "compacted":