v0.6.2-rc1

• 新增可选「回中优化」策略：长距离跳转时可先回到画布中心再继续绘制，提高稳定性，并在部分图案中小幅缩短绘制时间；生成结果会显示回中次数、省时估算和触发阈值。
• 优化换色、色槽选择、画笔/菜单操作的按键时序：使用更保守的可靠按键与等待间隔，降低串键、漏按、选错色槽的概率；代价是换色和调色阶段耗时会增加。
• 修复固件刷写前串口释放不完整的问题，减少端口 busy、需要重启应用或重新插拔设备的情况。
• 改进固件刷写工具链检测、修复提示和刷写页面体验，并补充英文/国际化界面支持。
• Added an optional recenter optimization strategy: for long-distance jumps, the cursor can return to the canvas center before continuing. This improves drawing stability and can slightly reduce total drawing time for some images. Generation results now show recenter count, estimated time saved, and trigger threshold.
• Improved input timing for color changes, palette slot selection, brush setup, and menu operations. These actions now use more conservative reliable button presses and settle waits to reduce missed inputs, repeated inputs, and incorrect palette selection. The tradeoff is longer time spent during color/menu operations.
• Fixed a serial-port cleanup issue before firmware flashing, reducing cases where flashing fails because the selected port is still busy.
• Improved firmware flashing/toolchain diagnostics and the flasher page experience, with added English/i18n support.