fix: address verified review findings (api-transport-download-1)

Signed-off-by: bircni <bircni@icloud.com>

docs/migration-1.0.md

@@ -261,7 +261,9 @@ changed meaning:
 - `api`: `--field` (`-f`) sent a string and `--Field` (`-F`) a typed value. Now
   `--raw-field` / `-f` sends a string and `--field` / `-F` a typed value, so the
   shorthands behave as before. `--data` / `-d` became `--input FILE` (or `-` for
-  stdin), and `--output` / `-o` became `--output-file`.
+  stdin), and `--output` / `-o` became `--output-file`. `api` exits 1 on a response outside
+  2xx (0.16 printed the body and exited 0), `-F key=@FILE` keeps the file's trailing newline,
+  and `--output-file` refuses to replace an existing file.
 
 ## Changed positional arguments