Task 4.1: new test proving a snapshot-restored PENDING job (valid
resreq) reaches the real, live sched_allocator() thread's
sched_make_allocation() entry point without crashing -- the exact
bug-1569-class failure task 1.2 closed for the snapshot-load path.
New file (not an extension of test_snapshot_save_load.c) since driving
the real allocator needs scheduler.c's full dependency closure, too
heavy for that file's deliberately lean core-only TU. Follows the
already-established pattern from test_scheduler_connect.c /
test_scheduler_backpressure.c / test_scheduler_dispatch_commit.c: link
the real scheduler.c, wrap xcecli_start/xcecli_join, start a real
sched_init(), feed jobs directly into core.jbuf to drive the live
allocator thread. Wired into meson.build as a new executable/test.
Verified with two fault-injection experiments (reverted after):
disabling task 1.2's schedobj construction call makes this test fail
cleanly via its own assertion; going further and removing that
assertion reproduces a genuine ASAN-caught SEGV in the real allocator
path -- concrete proof this test would have caught bug-1569's failure
shape. Both polling loops (jbuf drain, decision wait) are bounded
(2s timeout, 5ms poll) -- no hang risk; confirmed non-flaky across 10
consecutive runs.
Requirements: 2.2, 2.4
