[T0] Remove the parser Feature
Breaking: retire the legacy argument parsing in favor of picker
> [!NOTE]
>
> This is a **Breaking Change** planned for Mingling 0.5.0.
## Background
In 0.3.0, Mingling introduced the `picker` feature, which provides more powerful parameter parsing capabilities. At that point, the original `parser` feature became inadequate.
The `parser` feature was a temporary argument parsing solution created in the early stages of the project. While it can handle basic argument parsing tasks, its functionality is incomplete and has many limitations (see the [Picker2 issue](_add-picker2) for the full list).
## Plan
Completely remove the `parser` feature in 0.5.0. This will directly affect downstream users of the `parser` feature — they must migrate to `picker` (or handle parsing manually).
## Tasks
- [ ] Identify all usages of the `parser` feature across the codebase, examples, and docs
- [ ] Migrate internal usages (tests, examples, dev-dependencies) to `picker`
- [ ] Remove the `parser` feature from `mingling` and its dependency (`size`)
- [ ] Remove parser-related modules and public API
- [ ] Update docs and helpdoc examples
- [ ] Note the downstream migration path in the changelog
## 🕘 Progress
- [ ] In Progress
- [ ] Complete
Written by @Weicao-CatilGrass