The targeted-specialization work (jolt-ffn) concluded that the constant-factor
gap vs JVM is structural, not per-form: three targeted passes (field-read,
inline cache, ctor descriptor-bake) all came back flat. mandelbrot (pure
compute) is ~15x off JVM and that's the floor — Janet bytecode VM + mark-sweep
GC + indirect calls.
This doc hands off the successor epic (jolt-5vsp): the foundational levers
(native codegen, GC-pressure reduction, deeper devirt+inline) and, importantly,
the spike to run first — localize the 15x floor by comparing jolt-compiled vs
hand-written-Janet vs JVM mandelbrot before committing to any big lever. Also
records what not to repeat.
