feat: add HOOK_DETAIL_JOB_STOP/RESUME; fix xce_reply ordering after AFTER_EVENT hooks (P0-4a)

- cluster_def.h: add struct tag `cluster_s` to cluster_t to resolve
  conflicting typedef with persist.h forward declaration
- cluster_def.h: add HOOK_DETAIL_JOB_STOP and HOOK_DETAIL_JOB_RESUME enum
  values after HOOK_DETAIL_JOB_RUSAGE_UPDATE
- job.c on_job_stop(): replace mark_job_update() call with direct
  xce_run_hooks(BEFORE/AFTER, HOOK_DETAIL_JOB_STOP) so WAL writer
  records stop events with the correct detail value
- job.c on_job_resume(): same pattern with HOOK_DETAIL_JOB_RESUME
- job.c do_clr_preason(): fix typo — second hook call was HOOK_BEFORE_EVENT
  instead of HOOK_AFTER_EVENT (double-before, zero-after bug)
- join.c handle_worker_join(): move xce_reply() to after HOOK_AFTER_EVENT
  so client ACK is not sent before WAL write completes (durability fix)
- testsuite/test_hooks.c: new TDD tests for JOB_STOP/RESUME enum values
- testsuite/controller_test.c + meson.build: register test_hooks suite

Reply ordering audit results:
  job.c handle_jobsubmit: reply before AFTER_EVENT — intentional (jobid
    returned to client before scheduler notification; WAL hook belongs in
    BEFORE_EVENT for this path, handled in Task 13)
  job.c do_set_preason: reply before set_preason() loop — intentional
    fire-and-forget (no AFTER_EVENT hook at top level)
  job.c do_clr_preason: reply before loop — same fire-and-forget pattern
  job.c do_jobcontrol_op: no AFTER_EVENT hook, reply only — OK
  join.c handle_worker_join: FIXED (reply moved after AFTER_EVENT)
  worker.c on_worker_update/dead: reply after all hooks — OK
  cluster.c: AFTER_EVENT hooks are internal (no reply) — OK

src/controller/testsuite/controller_test.c

@@ -10,6 +10,7 @@ extern void test_persist_wal(void);
 extern void test_persist_schema(void);
 extern void test_persist_checkpoint(void);
 extern void test_persist_recovery(void);
+extern void test_hooks(void);
 
 void setUp(void) { return; }
 
@@ -89,6 +90,7 @@ int main(int argc, char* argv[])
     TEST(test_persist_schema);
     TEST(test_persist_checkpoint);
     TEST(test_persist_recovery);
+    TEST(test_hooks);
 
     return UNITY_END();
 }

src/controller/testsuite/test_hooks.c

@@ -0,0 +1,40 @@
+#include <stdio.h>
+
+#include <unity/unity.h>
+
+#include "xce/cluster_def.h"
+
+static void test_hook_detail_job_stop_exists(void)
+{
+    /* HOOK_DETAIL_JOB_STOP must be defined and distinct from JOB_UPDATE */
+    int stop_val   = (int)HOOK_DETAIL_JOB_STOP;
+    int update_val = (int)HOOK_DETAIL_JOB_UPDATE;
+    TEST_ASSERT_TRUE(stop_val != 0);
+    TEST_ASSERT_TRUE(stop_val != update_val);
+    printf("test_hook_detail_job_stop_exists: PASS\n");
+}
+
+static void test_hook_detail_job_resume_exists(void)
+{
+    int resume_val = (int)HOOK_DETAIL_JOB_RESUME;
+    int update_val = (int)HOOK_DETAIL_JOB_UPDATE;
+    TEST_ASSERT_TRUE(resume_val != 0);
+    TEST_ASSERT_TRUE(resume_val != update_val);
+    TEST_ASSERT_TRUE(resume_val != (int)HOOK_DETAIL_JOB_STOP);
+    printf("test_hook_detail_job_resume_exists: PASS\n");
+}
+
+static void test_hook_detail_job_stop_and_resume_are_distinct(void)
+{
+    TEST_ASSERT_NOT_EQUAL((int)HOOK_DETAIL_JOB_STOP, (int)HOOK_DETAIL_JOB_RESUME);
+    printf("test_hook_detail_job_stop_and_resume_are_distinct: PASS\n");
+}
+
+void test_hooks(void)
+{
+    printf("\n>> hook detail enum tests\n\n");
+
+    RUN_TEST(test_hook_detail_job_stop_exists);
+    RUN_TEST(test_hook_detail_job_resume_exists);
+    RUN_TEST(test_hook_detail_job_stop_and_resume_are_distinct);
+}