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/frontend/apiserver/backend/convert.go

@@ -57,6 +57,7 @@ func cJobArrayToModels(jobArray *C.xce_job_submit_t) []*models.JobInfo {
 		resReq:      goString(s.resreq),
 		minTasks:    int(s.mintasks),
 		maxTasks:    int(s.maxtasks),
+		fromHost:    goString(s.from_host),
 	}
 	if s.start_info != nil {
 		si := s.start_info
@@ -97,6 +98,7 @@ func cJobToModel(job *C.xce_job_t) *models.JobInfo {
 			resReq:      goString(s.resreq),
 			minTasks:    int(s.mintasks),
 			maxTasks:    int(s.maxtasks),
+			fromHost:    goString(s.from_host),
 		}
 		if s.start_info != nil {
 			si := s.start_info
@@ -311,6 +313,9 @@ func modelJobToSubmit(job *models.JobInfo) (*C.xce_job_submit_t, *C.job_submit_d
 	if job.ResReq != "" {
 		sd.resreq = C.CString(job.ResReq)
 	}
+	if job.FromHost != "" {
+		sd.from_host = C.CString(job.FromHost)
+	}
 	sd.mintasks = C.uint(job.NumProcessors)
 	if sd.mintasks == 0 {
 		sd.mintasks = 1
@@ -347,6 +352,7 @@ func freeJobSubmit(js *C.xce_job_submit_t, sd *C.job_submit_data_t, si *C.job_st
 		C.free(unsafe.Pointer(sd.user_group))
 		C.free(unsafe.Pointer(sd.job_description))
 		C.free(unsafe.Pointer(sd.resreq))
+		C.free(unsafe.Pointer(sd.from_host))
 		C.free(unsafe.Pointer(sd))
 	}
 	if js != nil {