Move CI, dev tools, and configs from root-level scattered locations into
a
unified `dev/` directory structure. Update all references across build
scripts, documentation, and editor configurations.

Also consolidate editor config generation into build.rs for automated
synchronization of rust-analyzer settings across VS Code and Zed.

Remove the generic parameter `C` from `DirectoryEnvironmentSetup`,
making it a unit struct that no longer requires `::<C>::default()` for
construction. Update the `ProgramSetup` impl and the `setup` method
signature accordingly, and improve the doc comments.

BREAKING CHANGE: Replace the `build`/`builds` feature system with
compile-time macro-driven generation. `gen_program!()` now automatically
invokes `build_comp!()` and `build_pathf!()` when the `comp`/`pathf`
features are enabled, eliminating the need for `build.rs` and
`[build-dependencies]` blocks.

This removes the `build` feature, the `mingling::build` module, and all
related build-time API functions. Completion scripts are now written to
`{target_directory}/mingling/` instead of `target/release/`. The
`mingling_cli` uses `build_comp!("mling")` for its custom binary name.

BREAKING CHANGE: `#[completion]` functions must now take `ShellContext`
by value instead of `&ShellContext`. Reference parameters are reserved
for resource injection.

Remove the `pack!`, `pack_err!`, `pack_structural!`, and
`pack_err_structural!` macros, replacing all pipeline type definitions
with `#[derive(Grouped)]` and `#[derive(Grouped, Wrap)]` attributes.
This changes the generated struct shape from named-field structs with an
`inner` field to tuple structs accessed via `.0`, and removes the
auto-generated `name` and `info` fields from error types.

Add `#[derive(Wrap)]` to treat a struct as its inner type, generating
`From`, `Deref`, and `DerefMut` implementations. Supports single-field
structs or multi-field structs with a `#[wrap]`-marked field.

The legacy `parser` feature and its module tree (`mingling::parser`,
`Argument`, `Picker`, `Pickable`, etc.) have been fully removed and
replaced by the `picker` feature powered by `arg-picker`.

BREAKING CHANGE: Remove `parser` feature and use `picker` instead.
Migration guide: Replace `features = ["parser"]` with
`features = ["picker"]` and update API usage per the provided table.