Adds the Meltingplot vendor bundle with 5 printer models:
- CHX 350 (880x422x943, RepRapFirmware/Duet)
- MBL 133/136/308/480 (RepRapFirmware/Duet)
Each model ships 0.4/0.6/0.8/1.0/1.2 nozzle variants. Layer height
presets span 40-60% of the nozzle diameter and deliberately avoid
heights that divide the Z screw lead evenly (CHX: 1204 ball screw,
4 mm lead; MBL: TR4x2 trapezoidal screw, 8 mm lead) so periodic
screw error does not repeat as banding.
All printers use 2.85 mm filament, so the bundle carries its own
filament library (PLA, StoneFil, ABS, TitanX, ASA, PETG, PA6 CF HT,
STYX 12, PP 9-2, PET-CF15, Extrudr PLA NX2 Matt, Igus iglidur J260)
with the 2.85 mm diameter pinned once in the vendor-local
fdm_filament_common base.
Machine limits mirror the printers' firmware configuration; machine
limit emission is disabled so the values only feed the time estimator.
