Build, test, and debug regular expressions
Matches content wrapped in curly braces where `{` is at the start of a line and `}` at the end (multiline mode). Two lazy capture groups split the enclosed text into a name portion (group 1) and a trailing numeric ID (group 2), so `{John42}` yields 'John' and '42'. Useful for parsing name-ID records in config or data files, one entry per line.