loadMicroPythonProgram only forwarded main.py (or files[0]) to the
bridge for raw-paste injection. Any auxiliary module the project
imported (mylib.py, drivers, etc.) never reached the device, so
`import mylib` died with ModuleNotFoundError.
Build a Python prelude that writes every other .py file to the
MicroPython filesystem via raw REPL, then runs main.py in the same
paste. JSON.stringify produces an ASCII-safe Python-compatible string
literal for the file body, which keeps the prelude inside the existing
chunked-UART path Esp32Bridge already uses to feed the 128-byte FIFO.
The RP2040 path was already multi-file via sim.loadMicroPython(files),
so it stays untouched.
Reproduces with the project shared in the bug report:
https://velxio.dev/project/ac7e285c-8dc3-4d51-8751-b4aba9912f9e