fix(telemetry): resolve phase-7 clang-tidy findings

- OTelCollector::formatName made static (no member state); braces added;
  <cctype> added for std::tolower.
- Telemetry.cpp getMeter(): braces around single-statement if.
- GetMeter.cpp: drop unused <opentelemetry/metrics/meter.h> and
  sync_instruments.h; add <xrpl/beast/utility/Journal.h> and <memory>;
  make sdkProvider const.
- ValidationTracker.h: add <cstddef> for std::size_t.
- detail/ValidationTracker.cpp: use std::views::reverse range-based loop;
  add <ranges>.
- test ValidationTracker.cpp: use auto for cast result.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/tests/libxrpl/telemetry/GetMeter.cpp

@@ -17,18 +17,18 @@
 
 #ifdef XRPL_ENABLE_TELEMETRY
 
+#include <xrpl/beast/utility/Journal.h>
 #include <xrpl/telemetry/Telemetry.h>
 
 #include <gtest/gtest.h>
-#include <opentelemetry/metrics/meter.h>
 #include <opentelemetry/metrics/meter_provider.h>
 #include <opentelemetry/metrics/provider.h>
-#include <opentelemetry/metrics/sync_instruments.h>
 #include <opentelemetry/nostd/shared_ptr.h>
 #include <opentelemetry/sdk/metrics/meter_provider.h>
 #include <opentelemetry/sdk/metrics/meter_provider_factory.h>
 
 #include <cstdint>
+#include <memory>
 #include <string>
 
 using namespace xrpl;
@@ -85,7 +85,7 @@ TEST(GetMeter, global_provider_meter_accepts_updown_counter)
     // A views-less SDK MeterProvider with no reader is sufficient to prove the
     // API contract: it hands out a real (non-noop) Meter that creates working
     // instruments. No exporter/reader means no background threads or network.
-    std::shared_ptr<metrics_sdk::MeterProvider> sdkProvider =
+    std::shared_ptr<metrics_sdk::MeterProvider> const sdkProvider =
         metrics_sdk::MeterProviderFactory::Create();
     metrics_api::Provider::SetMeterProvider(
         opentelemetry::nostd::shared_ptr<metrics_api::MeterProvider>(sdkProvider));

src/tests/libxrpl/telemetry/ValidationTracker.cpp

@@ -176,7 +176,7 @@ TEST_F(ValidationTrackerTest, MaxPendingEventsTrimming)
     for (std::size_t i = 0; i < kCount; ++i)
     {
         auto const hash = makeHash(i + 1);
-        LedgerIndex const seq = static_cast<LedgerIndex>(i + 1);
+        auto const seq = static_cast<LedgerIndex>(i + 1);
         tracker_.recordOurValidation(hash, seq);
         tracker_.recordNetworkValidation(hash, seq);
     }