cleanup, docs

site/doc/pages/file_truncate.txt

@@ -1,9 +1,20 @@
-file_truncate
+:sig
+bool file_truncate(String path, u64 size)
 
-Structural filesystem operation across the wasm host membrane. All path arguments are policy-gated through the same guest file/write roots as other file APIs and return false on denial or OS error.
+:params
+path : file to resize
+size : new length in bytes
+return value : true on success
+
+:content
+Truncates (or extends) a file to exactly `size` bytes. Shrinking discards trailing bytes; growing pads with zero bytes.
+
+:example
+file_put_contents("/tmp/doc-truncate.txt", "hello world");
+file_truncate("/tmp/doc-truncate.txt", 5);
+print(file_get_contents("/tmp/doc-truncate.txt"), "\n");
 
 :see
 >sys
-
-:example
-print("file_truncate example\n");
+file_put_contents
+file_stat