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, 6 insertions, 2 deletions

diff --git a/mingling_macros/src/func/program_fallback_gen.rs b/mingling_macros/src/func/program_fallback_gen.rs
index df53c60..1f3fdce 100644
--- a/mingling_macros/src/func/program_fallback_gen.rs
+++ b/mingling_macros/src/func/program_fallback_gen.rs
@@ -16,8 +16,12 @@ pub(crate) fn program_fallback_gen_impl(_input: TokenStream) -> TokenStream {
     };
 
     let expanded = quote! {
-        ::mingling::macros::pack!(ErrorRendererNotFound = String);
-        ::mingling::macros::pack!(EntryFallback = Vec<String>);
+        #[derive(::mingling::Grouped, ::mingling::Wrap, Default)]
+        pub struct ErrorRendererNotFound(pub ::std::string::String);
+
+        #[derive(::mingling::Grouped, ::mingling::Wrap, Default)]
+        pub struct EntryFallback(pub ::std::vec::Vec<::std::string::String>);
+
         #pack_empty
     };
     TokenStream::from(expanded)