nx_ferment_thermal_test.nx

nx_ferment_thermal_test.nx -- smoke for nx_ferment_thermal (R1). Proves hardware temperature control that is SAFE BY CONSTRUCTION: - unsafe setpoints are clamped below culture-kill (1-2) - command is heat-only (4) and bounded (5-6) - a room-temp vessel is driven into the 43 C yogurt neighborhood (7-8) - temperature NEVER reaches culture-kill dynamically (9, 12) - a 70 C request is clamped to 54 C and the loop converges to the CLAMPED safe temp, never the unsafe target (10-12) Exit code = failed assertion number; 0 = all pass.