- Add `#[must_use]` to public constructors and getters
- Change `init_with_config` to accept `&PathfinderConfig` instead of
  owned value
- Refactor `map_or_else` and `or_insert_with` for clippy compliance
- Add `#![deny(clippy::pedantic)]` and `#![deny(clippy::nursery)]`
- Document error cases in public API docs
- Simplify duplicated dispatcher_clap analysis logic

Remove the BasicStructPattern from pathf's pattern analyzer to eliminate
noise from plain structs not associated with any Mingling macro.

Also clean up the now-unused `basic_struct` module and update the
integration test to assert plain structs are no longer collected.

Add `Metadata<B>` trait and `#[metadata(Entry)]` attribute macro
to attach arbitrary, compile-time-typed metadata to entries.
Implement `ProgramCollect::get_metadata<T>()` for runtime retrieval,
backed by a global registry populated by `register_metadata!`.

Extend `pathf` with `MetadataPattern` to resolve metadata types
across modules at build time. Add two examples demonstrating
metadata usage with and without pathf integration.

Use `parse_args_with` with `Punctuated<Path, Comma>` to correctly
identify `Groupped` and `GrouppedSerialize` derive macros, fixing a
bug where enums and unions were not properly detected

dispatcher_clap

Add `PathfinderConfig` struct to control dispatch tree extraction,
and wire `use_dispatch_tree` through `DispatcherPattern`,
`init_with_config`,
and `analyze_and_build_type_mapping_for`. Expose config and wrapper
from `mingling_core` under the `pathf` feature.