dc-upkeep-7: allow larger command-file media

apps/deckcraft-cli/src/help.rs

@@ -72,8 +72,9 @@ Each --cmd is one command: COMMAND is a command id, then `=`, then the command's
 JSON object. Quote it for the shell. A command that needs no parameters is just its id.
 
 --cmd-file FILE reads the same commands from a UTF-8 text file, one per line, avoiding shell quoting
-and command-line length limits. Blank lines and full-line # comments are ignored, as is surrounding
-whitespace. CRLF line endings and an optional UTF-8 BOM at the start of the file are accepted.
+and command-line length limits. Each line can be up to 16 MiB, including commands with embedded
+media data. Blank lines and full-line # comments are ignored, as is surrounding whitespace. CRLF
+line endings and an optional UTF-8 BOM at the start of the file are accepted.
 Repeat --cmd-file or mix it with --cmd: commands execute in the order those options appear.
 File errors name the path; line-reading, JSON and command errors also name the line number.
 

apps/deckcraft-cli/src/main.rs

@@ -455,7 +455,7 @@ enum CommandSource {
     File(String),
 }
 
-const MAX_COMMAND_FILE_LINE_BYTES: usize = 1024 * 1024;
+const MAX_COMMAND_FILE_LINE_BYTES: usize = 16 * 1024 * 1024;
 
 fn read_command_file_line(reader: &mut impl std::io::BufRead, line: &mut Vec<u8>) -> std::io::Result<bool> {
     line.clear();