KawaiiSpinner used a two-phase clear+redraw approach: first write
\r + spaces to blank the line, then \r + new frame. When running
inside prompt_toolkit's patch_stdout proxy, each phase could trigger
a separate repaint, causing visible flickering every 120ms.
Replace with a single \r\033[K (carriage return + ANSI erase-to-EOL)
write so the line is cleared and redrawn atomically.
- Modified the `_wrap` function to append a failure suffix without applying red coloring, simplifying the failure message format.
- Introduced temporary debug logging in the `execute_code` function to track enabled and sandbox tools, aiding in troubleshooting.
- Captured stdout at spinner creation to prevent redirection issues from child agents.
- Replaced direct print statements with a new `_write` method for consistent output handling during spinner animation and final message display.
- Enhanced code maintainability and clarity by centralizing output logic.
- Eliminated the `_raw_write` function to simplify output handling in the `KawaiiSpinner` class.
- Updated spinner animation and final message display to use standard print statements, ensuring compatibility with prompt_toolkit.
- Improved code clarity and maintainability by reducing complexity in the output rendering process.
- Added a new function `_raw_write` to write directly to stdout, bypassing prompt_toolkit's interference with ANSI escapes and carriage returns.
- Updated the `KawaiiSpinner` class to utilize `_raw_write` for rendering spinner animations and final messages, ensuring proper display in terminal environments.
- Improved the clarity of output handling during spinner operations, enhancing user experience during tool execution.
