refactor: address package loader review feedback

README.md

@@ -63,6 +63,8 @@ the native bootstrap accepts either a no-argument `main` or `main proc(init proc
 
 source loading uses the supplied `io.Io` for opening, reading, and closing files. `io.open` accepts a borrowed zero-terminated slice (`[;0]u8`), including `init.args.values[index]` without copying its storage. the bootstrap supports checked sentinel-slice construction with `pointer[..length;0]`. `io.read_all(allocator, reader, maximum)` reads to EOF into a caller-owned `ArrayList(u8)`; release it with `arraylist.deinit`. it frees partial storage on error and consumes one extra byte to distinguish an exact-size input from a limit violation. the driver maps `limit_exceeded` to `source_too_large` at its `u32` source-size limit.
 
+`@std/fs` contains the Darwin filesystem operations used by source loading: `canonical` returns an owned symlink-resolved path (free with the same allocator), while `kind` and `exists` classify paths without exposing C mode bits. `open_directory` returns an owned handle released with `close_directory`; `next` returns a borrowed entry whose name expires on the next call or close. enumeration order is unspecified. `read_file(allocator, runtime, path, maximum)` reads a regular file through the supplied `io.Io`, closes it on success/error, and returns caller-owned bytes released with `arraylist.deinit`; exceeding the bound returns `limit_exceeded`. metadata and directory discovery use the host filesystem. the compiler's `@source/loader` retains project-root/import rules, production-file filtering, deterministic sorting and the `u32` source-size limit, with no direct libc calls.
+
 a recursive example is in [programs/factorial.hon](programs/factorial.hon); `./build/honey run programs/factorial.hon` prints `120`.
 
 an iterative example is in [programs/iterative_factorial.hon](programs/iterative_factorial.hon); `./build/honey run programs/iterative_factorial.hon` also prints `120`.