refactor!: replace pack! macros with derive-based pipeline types

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.

1 files changed, 2 insertions, 1 deletions

diff --git a/docs/pages/12-exit-code.md b/docs/pages/12-exit-code.md
index 6828cde..8fa320c 100644
--- a/docs/pages/12-exit-code.md
+++ b/docs/pages/12-exit-code.md
@@ -29,7 +29,8 @@ In a Chain or Renderer, inject `ResExitCode` to modify the exit code:
 ```rust
 @@@use mingling::res::ResExitCode;
 @@@use mingling::setup::ExitCodeSetup;
-@@@pack!(EntryCheck = Vec<String>);
+@@@#[derive(Grouped, Wrap)]
+@@@pub struct EntryCheck(Vec<String>);
 #[chain]
 fn handle_check(_args: EntryCheck, ec: &mut ResExitCode) {
     // Modify exit code when check fails