PHLEGM v4 - Machine Transition / Micro-code Recompile Fix
Checkpoint: 2026-0927-1618-5198 America/Phoenix

- A MACHINE/CHIPSET change now hard-invalidates the prior compiled CPU execution image before loading the replacement definition.
- Compiled micro-op entry points, IRQ/NMI programs, device-op pool, and opcode decode tables are cleared as one execution-image boundary.
- The emulation run slice now uses an execution-image generation guard. If GUI message dispatch changes machines/chipsets mid-slice, the old slice exits immediately instead of resuming against the new compiled image with stale pacing targets.
- Fresh cartridge-based machines with no inserted media remain powered OFF. They no longer read an unmapped $FFFF reset vector and fault on $FF before a cartridge is inserted.
- Session/state restore behavior is unchanged: restored sessions reuse their resident compiled definition image rather than running a fresh-machine self-test.
- Source/text files remain CRLF-only.
