Elevates the normal-mode/simulation-mode driver equivalence guarantee
from a one-line architectural description in CLAUDE.md to an enforced
steering constraint (scheduler-driver-equivalence.md), backed by
bug-1611/bug-1613 as concrete evidence of violation. Scopes the fix as
its own spec (scheduler-sim-decision-parity, requirements + design)
rather than reopening the closed scheduler-core spec or folding it
into scheduler-sim-repl-verbosity's explicitly narrower boundary.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
test_core_isolation.c's build-time proof (nm(1) undefined-symbol scan of
sched_core_isolation_lib) previously covered only core.c -- core.c's own
800-line-cap siblings, holding scheduling logic just as boundary-sensitive
as core.c itself, were "isolation-clean by review" only, with nothing
mechanical catching a regression. Extends sched_core_isolation_lib to
compile all four files together, and the source-text scans (forbidden
headers/symbols, wall-clock calls) to also cover core_events.c/
core_session.c. core_clock.c joins only the nm(1) layer, not the
wall-clock text scan -- it's the one sanctioned exception carrying the
core family's single legitimate clock_gettime() call.
The file was untouched since before scheduler-core and still described
a plain plugin-selects-at-runtime engine with a generic meson build
command. Documents the actual core/driver split, the picker plugin
interface and its builtin_fcfs/fcfs.c split, the simulation driver and
replay/recording machinery, and the interactive REPL, plus the correct
/xce-build invocation and the project's 800-line-file-cap convention
this module's several *_events.c/*_session.c-style splits follow.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>