Migrate `mingling_core::pathf` into `mingling_core::builds::pathf` and
re-export from `mingling::build`.  Update all references from
`mingling::builds` and `mingling::pathf` to `mingling::build`.

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 module-level docs for the hook system, enhance doc examples for
macros
with usage syntax, fix typos in cross-references, and hide internal
debugging
macros and mock types from public documentation

Support `&mut T` resource parameters in async chain functions by using
an extract-store pattern that avoids holding mutable borrows across
await
points. Remove the previous compile-time rejection of this combination.