merge: sync Rongsong's scheduler-framework (122 commits, 070c7869..f01ae353)

Introduces WAL replay field-completeness fixes (bug-1687..1697, 1731), scheduler snapshot job-allocation restore, heap UAF fixes (vtask_enq, xcealloc, builtin_fcfs, limit), HA fixes (bug-1694/1695/1696), xceadmin retry, worker signal-exit severity, and their test suites.

Conflicts resolved keeping both sides (drop-audit passed):
- worker.c: mark_worker_jobs_exit (bug-1509 B1) + fetchfile_signal_worker_disconnect (bug-1693)
- handler.go: DefaultBroker.Publish (EventJobFinished) + bug-1731 logging
- config_repl.c / test_config_repl.c: our ns-resolution comment / unique-tmpdir
- test_dispatch_commit.c: both B3-UNKWN and bug-1697 start_time assertions

Excluded Rongsong's bookkeeping per policy: .wolf/, .kiro/, CHANGES.md, reports/;
.claude/ + CLAUDE.md kept ours (his settings.json has machine-absolute paths).

src/lib/meson.build

@@ -189,6 +189,8 @@ libxce_test_src = ['testsuite/test.c',
                    'testsuite/test_wal_wire.c',
                    'testsuite/test_ctrlstatus.c',
                    'testsuite/test_vtask_admission.c',
+                   'testsuite/test_vtask_enq_race.c',
+                   'testsuite/test_xcealloc.c',
                    'raft/raft_sim.c',
                   ]