test(raft-apply-decoupling): apply/notify timing integration through the full pump (task 6.3)

Add test_apply_pump_integration.c (2 tests), no production changes.
Exercises the full live pump (real commit engine, real apply
dispatch, real hook subscribers) for both a job submission and a
fact: proves reply-after-visibility ordering for commands, and zero
fact-reaction side effects during a delayed-commit/quorum-loss
window (polled repeatedly across real time, not checked once).

Confirms Req 4.3 by construction, not assertion: the apply walk only
ever invokes apply_committed_entry() for LSNs already <= committed_lsn,
so a consumer acting on the post-apply notification never needs to
separately re-check a commit watermark.

Independently verifies apply_committed_entry()'s generic
HOOK_DETAIL_JOB_UPDATE routing (unchanged by task 6.1's _pad fix)
makes the type-specific sched.c/apiserver.c hook handlers
structurally unreachable for live-applied facts -- confirmed their
va_arg-typed signatures would type-confuse-crash if ever called with
the job_t* apply_committed_entry() actually passes, making the
single generic reaction spy a sound design, not a coverage gap.

Repo-wide audit confirms exactly 2 live call sites ever fire these
hook details (the guarded apply seam, and job_ctrl's legitimate
SIGCONT/SIGSTOP path) -- no orphaned third site.

src/controller/testsuite/controller_test.c

@@ -83,6 +83,7 @@ extern void test_replay_apply_seam(void);
 extern void test_apply_reapply_idempotency(void);
 extern void test_apply_correctness_verification(void);
 extern void test_apply_pump(void);
+extern void test_apply_pump_integration(void);
 
 void setUp(void) { return; }
 
@@ -235,6 +236,7 @@ int main(int argc, char* argv[])
     TEST(test_apply_reapply_idempotency);
     TEST(test_apply_correctness_verification);
     TEST(test_apply_pump);
+    TEST(test_apply_pump_integration);
 
     return UNITY_END();
 }