fix(tui): stabilize live todo progress

ui-tui/src/lib/liveProgress.ts

@@ -0,0 +1,34 @@
+import type { Msg, TodoItem } from '../types.js'
+
+export const isTodoDone = (todos: readonly TodoItem[]) =>
+  todos.length > 0 && todos.every(todo => todo.status === 'completed' || todo.status === 'cancelled')
+
+export const isToolShelfMessage = (msg: Msg | undefined) =>
+  Boolean(msg?.kind === 'trail' && !msg.text && !msg.thinking?.trim() && msg.tools?.length)
+
+const canHoldToolShelf = (msg: Msg | undefined) =>
+  Boolean(msg?.kind === 'trail' && !msg.text && (msg.thinking?.trim() || msg.tools?.length))
+
+export const appendToolShelfMessage = (prev: readonly Msg[], msg: Msg): Msg[] => {
+  if (!isToolShelfMessage(msg)) {
+    return [...prev, msg]
+  }
+
+  for (let index = prev.length - 1; index >= 0; index--) {
+    const candidate = prev[index]
+
+    if (canHoldToolShelf(candidate)) {
+      const next = [...prev]
+
+      next[index] = { ...candidate!, tools: [...(candidate!.tools ?? []), ...(msg.tools ?? [])] }
+
+      return next
+    }
+
+    if (candidate?.kind !== 'trail' || candidate.text) {
+      break
+    }
+  }
+
+  return [...prev, msg]
+}