docs: update Phase 9 docs and dashboard for push_metrics.py parity gauges

- Add Task 9.7a to Phase9_taskList.md documenting new gauges
- Add metric tables to 09-data-collection-reference.md (server_info,
  build_info, complete_ledgers, db_metrics, extended cache/nodestore)
- Update metric counts from ~50 to ~68 in 06-implementation-phases.md
- Add OTel MetricsRegistry gauge reference to telemetry-runbook.md
- Add 11 new panels to system-node-health.json Grafana dashboard
  (server state, uptime, peers, validated seq, last close info,
  build version, complete ledgers, db sizes, historical fetch rate,
  peer disconnects)
- Fix leftover merge conflict marker in 08-appendix.md
- Add ripplex/mseconds to cspell dictionary

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/scripts/levelization/results/loops.txt

@@ -17,8 +17,11 @@ Loop: xrpld.app xrpld.shamap
   xrpld.shamap ~= xrpld.app
 
 Loop: xrpld.app xrpld.telemetry
-  xrpld.telemetry ~= xrpld.app
+  xrpld.telemetry == xrpld.app
 
 Loop: xrpld.overlay xrpld.rpc
   xrpld.rpc ~= xrpld.overlay
 
+Loop: xrpld.overlay xrpld.telemetry
+  xrpld.telemetry == xrpld.overlay
+

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

@@ -257,7 +257,6 @@ xrpld.overlay > xrpl.basics
 xrpld.overlay > xrpl.core
 xrpld.overlay > xrpld.core
 xrpld.overlay > xrpld.peerfinder
-xrpld.overlay > xrpld.telemetry
 xrpld.overlay > xrpl.json
 xrpld.overlay > xrpl.protocol
 xrpld.overlay > xrpl.rdb
@@ -290,5 +289,7 @@ xrpld.shamap > xrpl.shamap
 xrpld.telemetry > xrpl.basics
 xrpld.telemetry > xrpl.core
 xrpld.telemetry > xrpl.nodestore
+xrpld.telemetry > xrpl.protocol
+xrpld.telemetry > xrpl.rdb
 xrpld.telemetry > xrpl.server
 xrpld.telemetry > xrpl.telemetry