merge: sync Rongsong's scheduler-framework into chatbot

Full merge of origin/scheduler-framework (scheduler-core restructure,
failover-adoption, WAL_JOB_DISPATCH, apiserver backend health/heartbeat,
build-time versioning, bug-1673/1676/1678/1679/1680).

Conflict resolution:
- scheduler: adopt Rongsong's scheduler-core architecture (driver loop,
  queue project/picker fields, resource bug-1569 fix)
- worker/controller_connector.c: keep Rongsong's reconnect/rejoin
  structure, PORT our bug-1509 resend_job_status onto the rejoin success
  path (his reconnect didn't re-report job state)
- apiserver backend: take Rongsong's health/heartbeat (supersedes our
  e505066 circuit breaker)
- group.c: keep our bug-1513 comment
- misc: take theirs for additive fixes (go_build versioning,
  test_group.c, persist.c RUSAGE_UPDATE, FilterRows bug-1680)

NOTE: our scheduler fixes (bug-1494 family dispatch-fail requeue,
PEND-reason classification) are NOT in Rongsong's branch — needs
verification/porting onto scheduler-core (separate follow-up).

Co-Authored-By: Claude <noreply@anthropic.com>

src/controller/sched.c

@@ -276,6 +276,25 @@ static int xcesched_push_workers(cluster_t* c)
     workers.workers = (xce_worker_t**)wlist.data;
     workers.count   = workers.n_total;
 
+    /* bug-1568 instrumentation: this is the FULL initial worker sync sent
+     * once, at on_scheduler_join() -- distinct from sched_worker_change()'s
+     * per-event incremental push (this file, above), which only fires
+     * AFTER a scheduler is already connected. A scheduler that connects
+     * before this controller's own resource_sync has completed its first
+     * poll cycle would see 0 resvals here even though this push path
+     * itself is working correctly. */
+    if (workers.n_total > 0) {
+        int total_resvals = 0;
+
+        for (i = 0; i < workers.n_total; i++) {
+            xce_worker_t* w = workers.workers[i];
+
+            total_resvals += (w != NULL) ? w->nresvals_to_sched : 0;
+        }
+        TRACE("%s initial sync: %d worker(s), %d total resval(s)", __func__,
+              workers.n_total, total_resvals);
+    }
+
     rc = xce_push_data_req(c->sched.ep, c->myhost, &data, check_controller, c,
                            100);
 
@@ -533,6 +552,14 @@ static int sched_worker_change(int type, int situation, void* data,
     if (c->sched.ep != NULL) {
         switch (situation) {
         case HOOK_AFTER_EVENT:
+            /* bug-1568 instrumentation: the controller-side count actually
+             * being pushed to the scheduler right now -- compare against
+             * core_build_worker()'s "WORKERS_PUSH carries N resval(s)"
+             * TRACE (scheduler/src/core_events.c) in the scheduler's own
+             * log for the same worker/timestamp to confirm the wire push
+             * itself is not where a resource value gets lost. */
+            TRACE("%s worker %s pushing %d resval(s) to scheduler", __func__,
+                  w->host.name, resvalist.count);
             xlist_init(&wlist, 2);
             xlist_store(&wlist, w);
             rc = xcesched_push_workerlist(c, &wlist);
@@ -544,11 +571,8 @@ static int sched_worker_change(int type, int situation, void* data,
     }
     mylock_unlock(&(c->sched.lock));
 
-#if 0
-    /*FIXME*/
-    free_name_val_list(&(w->host.resvals_to_sched),
-                       &(w->host.nresvals_to_sched));
-#endif
+    w->host.nresvals_to_sched = 0;
+    w->host.resvals_to_sched  = NULL;
     xlist_fini(&resvalist);
 
     return rc;