Merge branch 'pratik/otel-phase10-workload-validation' into pratik/otel-sync-diagnostics

Brings in the phase-10 revert of the nodestore read-latency histogram plus the
nudb_bytes -> stored_object_bytes rename.

Conflicts in MetricsRegistry.{h,cpp} resolved keeping both intents:

- MetricsRegistry.cpp: dropped everything that existed only to serve the
  reverted nodestore_read_us histogram -- the addSubMillisecondHistogramView()
  helper, its call site, the kSubMillisecondBoundaries array and the
  NodeStoreMetricNames.h include. Kept every view this branch registers
  (consensus round duration, sweep_malloc_trim_us, dns_resolve_latency_ms,
  overlay_dial_latency_ms) and the shared addHistogramView() base helper.
  Took the rename at the storage_detail observe() call site.

- MetricsRegistry.h: took phase-10's move of the four nodestore_state observe
  helpers and their ObserveFn sink from private to public, while keeping this
  branch's enriched Doxygen on observeNodeStoreTotals().

Also corrected the registered-view count in the 09 reference doc: neither side's
arithmetic survives the merge, since this branch adds four views phase-10 never
saw and the revert removes one. Ten views are registered now, not six or seven.

.github/scripts/levelization/results/ordering.txt

@@ -138,7 +138,9 @@ test.nodestore > test.jtx
 test.nodestore > test.unit_test
 test.nodestore > xrpl.basics
 test.nodestore > xrpl.config
+test.nodestore > xrpld.app
 test.nodestore > xrpld.core
+test.nodestore > xrpld.telemetry
 test.nodestore > xrpl.nodestore
 test.nodestore > xrpl.rdb
 test.overlay > test.jtx