The hosted Makefile writes include/version.h with FORCE as a prerequisite
(always regenerates), but Makefile.starkernel's own rule had no
prerequisite at all -- Make only rebuilds a target with no prerequisites
when the file is missing. Since both Makefiles write the same path with
incompatible content (the hosted version has no LITHOS_VERSION/
LITHOS_VERSION_STR at all), running a bare `make -f Makefile.starkernel`
after a hosted `make` build silently reused the wrong file and failed
deep in kernel_main.c with "LITHOS_VERSION_STR undeclared".
Added FORCE (declared .PHONY, matching the hosted Makefile's own existing
pattern) as include/version.h's prerequisite in Makefile.starkernel.
Verified the fix directly: poisoned version.h with a hosted build, then
ran a bare (non-clean) kernel build and confirmed it self-heals.
Full three-architecture acceptance: amd64 (logs/20260922-215333/),
aarch64 (logs/20260922-215803/), riscv64 (logs/20260922-220217/) -- all
three reach [zuse@Hera] ok>, zero UNKNOWN WORD.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
