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.

Dispatchers are now always registered at compile time, removing the
`with_dispatcher` / `with_dispatchers` methods and the
`PathfinderConfig` API. The `dispatch_tree` feature now only controls
the matching strategy (trie vs linear list).

Mark all source files with a comment indicating they are not optimized
for documentation purposes.

- 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

Add `#![deny(missing_docs)]` across multiple crates and fill in
documentation for all public items, including struct fields, enum
variants, trait methods, and proc macros.  Also mark two shell scripts
as executable.

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.

Add `mingling_pathf` sub-crate and `pathf` feature for automatic
resolution of Mingling type module paths at build time. Scans source
files, identifies macro invocations via pattern matchers, and generates
mapping files consumed by `gen_program!()`.

Add a `PatternAnalyzer` with an `AnalyzePattern` trait to detect and
extract struct declarations from Rust source files, supporting nested
inline modules.

Introduce the core pathfinding infrastructure with `ModulePathMapping`,
`MappingItem`, and `MinglingPathfinderError` types. Support recursive
module traversal, `pub use` re-export hoisting, and standard Rust
module resolution rules.