review #5: declare File stdlib native fns with the native keyword

File.* interface fns used 'pub fn ... effects(native)' while Directory, Http,
and the http client all use the canonical 'pub native fn ... effects(native)'
form documented in diagnostic RS (native fn must spell effects(native)).
Align File for consistency; FileError.message stays 'pub fn' (effects pure).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: Haofei

stdlib/fs/file.rssi

@@ -2,64 +2,64 @@ features: native
 
 resource File
 
-pub fn File.open(path: read Path) -> Result<File, FileError>
+pub native fn File.open(path: read Path) -> Result<File, FileError>
     effects(native)
 
-pub fn File.open_read(path: read Path) -> Result<File, FileError>
+pub native fn File.open_read(path: read Path) -> Result<File, FileError>
     effects(native)
 
-pub fn File.open_write(path: read Path) -> Result<File, FileError>
+pub native fn File.open_write(path: read Path) -> Result<File, FileError>
     effects(native)
 
-pub fn File.exists(path: read Path) -> Bool
+pub native fn File.exists(path: read Path) -> Bool
     effects(native)
 
-pub fn File.read_bytes(path: read Path) -> Result<fresh Bytes, FileError>
+pub native fn File.read_bytes(path: read Path) -> Result<fresh Bytes, FileError>
     effects(native)
 
-pub fn File.read_string(path: read Path) -> Result<String, FileError>
+pub native fn File.read_string(path: read Path) -> Result<String, FileError>
     effects(native)
 
-pub fn File.write_bytes(path: read Path, data: read Bytes) -> Result<Unit, FileError>
+pub native fn File.write_bytes(path: read Path, data: read Bytes) -> Result<Unit, FileError>
     effects(native)
 
-pub fn File.append_bytes(path: read Path, data: read Bytes) -> Result<Unit, FileError>
+pub native fn File.append_bytes(path: read Path, data: read Bytes) -> Result<Unit, FileError>
     effects(native)
 
-pub fn File.write_string_to_path(path: read Path, text: read String) -> Result<Unit, FileError>
+pub native fn File.write_string_to_path(path: read Path, text: read String) -> Result<Unit, FileError>
     effects(native)
 
-pub fn File.write_atomic(path: read Path, text: read String) -> Result<Unit, FileError>
+pub native fn File.write_atomic(path: read Path, text: read String) -> Result<Unit, FileError>
     effects(native)
 
-pub fn File.append_string(path: read Path, text: read String) -> Result<Unit, FileError>
+pub native fn File.append_string(path: read Path, text: read String) -> Result<Unit, FileError>
     effects(native)
 
-pub fn File.remove(path: read Path) -> Result<Unit, FileError>
+pub native fn File.remove(path: read Path) -> Result<Unit, FileError>
     effects(native)
 
-pub fn File.read_all(file: mut File) -> Result<fresh Bytes, FileError>
+pub native fn File.read_all(file: mut File) -> Result<fresh Bytes, FileError>
     effects(native)
 
-pub fn File.read_all_string(file: mut File) -> Result<String, FileError>
+pub native fn File.read_all_string(file: mut File) -> Result<String, FileError>
     effects(native)
 
-pub fn File.read_into(file: mut File, buffer: mut Buffer) -> Result<Bool, FileError>
+pub native fn File.read_into(file: mut File, buffer: mut Buffer) -> Result<Bool, FileError>
     effects(native)
 
-pub fn File.write(file: mut File, data: read Bytes) -> Result<Unit, FileError>
+pub native fn File.write(file: mut File, data: read Bytes) -> Result<Unit, FileError>
     effects(native)
 
-pub fn File.write_bytes_view(file: mut File, data: read BytesView) -> Result<Unit, FileError>
+pub native fn File.write_bytes_view(file: mut File, data: read BytesView) -> Result<Unit, FileError>
     effects(native)
 
-pub fn File.write_string(file: mut File, text: read String) -> Result<Unit, FileError>
+pub native fn File.write_string(file: mut File, text: read String) -> Result<Unit, FileError>
     effects(native)
 
-pub fn File.write_buffer(file: mut File, buffer: read Buffer) -> Result<Unit, FileError>
+pub native fn File.write_buffer(file: mut File, buffer: read Buffer) -> Result<Unit, FileError>
     effects(native)
 
-pub fn File.write_buffer_view(file: mut File, buffer: read BufferView) -> Result<Unit, FileError>
+pub native fn File.write_buffer_view(file: mut File, buffer: read BufferView) -> Result<Unit, FileError>
     effects(native)
 
 pub fn FileError.message(error: read FileError) -> String