FM25V02A-G write-enable fixture

Read fm25v02a-write-enable-latch.html first. Use an original Raspberry Pi
Pico with MicroPython v1.29.0 and the exact SOIC-8 FM25V02A-G. Assemble
the fixture with power disconnected. Verify the supply, chip select
and the specified ramp and startup times at the device.

Copy fm25v02a_wel.py to the board. From the MicroPython prompt:
    from fm25v02a_wel import run
    run(confirm_scratch=True)

The code intentionally writes 0x1234 on a dedicated chip. It leaves
the last successful test byte in place. Start from a cold power-up.

Host model tests on CPython, from this directory:
    python3 -m unittest -v

Use observations-blank.csv to record actual bench values.
