Tab completion does not work in the repl

### Version Glasgow 0.1.dev2721+g7c0ed65.d20251024 (CPython 3.13.7 on macOS-15.7.1-x86_64-i386-64bit-Mach-O) ### Description I ran `glasgow repl control-gpio --pins A0,A1,A2,A3,A4,A5,A6,A7 -V 5` and I can edit the commands as expected, eg cursor up/down and so on, but pressing tab just inserts a literal tab. If I run the Python interpreter that Glasgow is using by hand tab completion works in it. Also, the '>>>' prompt is purple when run by hand but grey in the Glasgow repl. In the Glasgow repl I can `import readline` and `readline.backend == 'editline'` ### Log file _No response_