refactor(todos): remove internal file-based todo system (#635)

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/converters/claude-to-pi.ts

@@ -109,8 +109,14 @@ export function transformContentForPi(body: string): string {
 
   // Claude-specific tool references
   result = result.replace(/\bAskUserQuestion\b/g, "ask_user_question")
-  result = result.replace(/\bTodoWrite\b/g, "file-based todos (todos/ + /skill:ce-todo-create)")
-  result = result.replace(/\bTodoRead\b/g, "file-based todos (todos/ + /skill:ce-todo-create)")
+  // Claude Code task-tracking primitives: current Task* API (TaskCreate/TaskUpdate/TaskList/TaskGet/TaskStop/TaskOutput)
+  // plus the deprecated legacy pair (TodoWrite/TodoRead). All map to the platform's task-tracking primitive.
+  result = result.replace(
+    /\bTask(?:Create|Update|List|Get|Stop|Output)\b/g,
+    "the platform's task-tracking primitive",
+  )
+  result = result.replace(/\bTodoWrite\b/g, "the platform's task-tracking primitive")
+  result = result.replace(/\bTodoRead\b/g, "the platform's task-tracking primitive")
 
   // /command-name or /workflows:command-name -> /workflows-command-name
   const slashCommandPattern = /(?<![:\w])\/([a-z][a-z0-9_:-]*?)(?=[\s,."')\]}`]|$)/gi