PHLEGM v6 firmware cache for CBM-3008

This directory intentionally contains no Commodore ROM binaries.
The machine's firmware.config.phlegm declares the accepted filenames, exact sizes, any known
CRC32 values, and a preferred source URL for generic on-demand acquisition.

Profile: European CBM 3000-series graphics-keyboard machine
Keyboard: normal/graphics
ROM generation: BASIC 2
Display: 40 x 25, fixed screen base $8000 (pre-CRTC), 50 Hz default
RAM: 8 KiB ($0000-$1FFF)

When an accepted CRC32 field is empty, PHLEGM still enforces the exact ROM byte size;
that slot will gain checksum enforcement when an authoritative per-device CRC is
recorded in firmware.config.phlegm.
