IPathQuery implementation backed by babashka.fs.
All operations return hive-dsl Results for railway composition.

Convenience API (stateless, default instance):
  (exists? path)           → Result<boolean>
  (directory? path)        → Result<boolean>
  (absolute-dir? path)     → Result<boolean>
  (resolve-first-dir [...]) → Result<string>
  (find-files path exts)   → Result<vec<string>>
  (expand-path path exts)  → vec<string> (rescue-wrapped)

DIP: consumers depend on IPathQuery protocol, not this impl.
Swap FsPathQuery for a test double via make-path-query or protocol.

IFilesystem implementation backed by babashka.fs + java.nio.
All operations return hive-dsl Results for railway composition.

Convenience API (stateless, default instance):
  (mkdirs! path)                 → Result<{:path}>
  (tmpdir! prefix)               → Result<{:path}>
  (atomic-write! path content)   → Result<{:path :bytes}>
  (lock! path timeout-ms)        → Result<{:lock}>
  (watch! path patterns handler) → Result<{:watcher}>

DIP: consumers depend on the IFilesystem protocol, not this impl.
Swap FsFilesystem for a test double via make-filesystem or the protocol.