PHLEGM v9 r77 - Default/Standalone Chipset POWER ON on Load

Source baseline: PHLEGM v9 r76.

Behavior:
- Fresh standalone/default CPU chipset startup and CHIPSET selection call the same
  POWER ON runtime entry point used for machine startup, rather than VmClear alone.
- Standalone POWER ON clears mutable RAM/state, initializes CFG reset registers,
  applies the declared reset_mode and reset_vector, and resets cycle scheduling.
- POWER STATUS/ON/OFF/TOGGLE, RESET, STEP, and RUN now respect power state for
  standalone chipsets as well as complete machines.
- Complete machine POWER ON still requires verified machine firmware, and
  cartridge-machine cold starts still follow their existing empty-slot policy.
- SESSION/STATE restoration is not cold-booted; saved CPU state is preserved.
- Self-tests are not skipped, and CPU behavior remains CFG-driven.

Validation: source-level Node regression available at
  tests/Default-Chipset-Power-On-r77.Tests.js
Native FreeBASIC compilation and physical emulator execution were not run here.
