Cleanup Makefile & Improve Dev Experience

#### Problem
- The repo has both a `Makefile` and a `Taskfile.yml`, with redundant commands. We should standardize on `Taskfile.yml` and remove `Makefile`.
- Scripts are split between `scripts/` and `hack/`, and they don’t work well together.
- Running the plugin locally is a pain—too many steps, not well-documented.

#### Proposed Fix
- Remove `Makefile` to avoid duplication.
- Organize scripts in a single, consistent place.
- Improve local dev setup so it’s easier to run and debug.
- Document the procedure to run a test deployment of the local code.

比较 Makefile 和 Taskfile.yml，然后盘点 scripts/ 和 hack/ 目录以及当前在本地运行插件的步骤。完成的标准是：移除冗余的任务命令，脚本统一放在一个位置，记录本地执行和调试过程，并记录测试部署流程。

由索引模型根据 Issue 内容生成。