fix(telemetry): address clang-tidy CI failures on phase9

- MetricsRegistry.cpp: concatenate nested namespaces, add missing
  direct includes (Journal.h, string, string_view, cstdint), suppress
  readability-convert-member-functions-to-static in #else stubs by
  referencing enabled_ member, void unused instanceId parameter.
- MetricsRegistry test: add missing direct includes (Log.h, Journal.h,
  uint256.h, io_context.hpp, optional, stdexcept, string), make
  throwUnimplemented() static, add [[nodiscard]] to getOpenLedger/
  isStopping/getTrapTxID overrides, make const-eligible registry const.
- PerfLogImp.cpp: add braces around if/else body per
  readability-braces-around-statements.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/tests/libxrpl/telemetry/MetricsRegistry.cpp

@@ -19,10 +19,19 @@
 
 #include <xrpld/telemetry/MetricsRegistry.h>
 
+#include <xrpl/basics/Log.h>
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/beast/utility/Journal.h>
 #include <xrpl/core/ServiceRegistry.h>
 
+#include <boost/asio/io_context.hpp>
+
 #include <gtest/gtest.h>
 
+#include <optional>
+#include <stdexcept>
+#include <string>
+
 using namespace xrpl;
 
 namespace {
@@ -37,8 +46,8 @@ namespace {
  */
 class MockServiceRegistry : public ServiceRegistry
 {
-    [[noreturn]] void
-    throwUnimplemented() const
+    [[noreturn]] static void
+    throwUnimplemented()
     {
         throw std::logic_error("MockServiceRegistry: method not implemented");
     }
@@ -195,12 +204,12 @@ public:
     {
         throwUnimplemented();
     }
-    OpenLedger&
+    [[nodiscard]] OpenLedger&
     getOpenLedger() override
     {
         throwUnimplemented();
     }
-    OpenLedger const&
+    [[nodiscard]] OpenLedger const&
     getOpenLedger() const override
     {
         throwUnimplemented();
@@ -250,7 +259,7 @@ public:
     {
         return nullptr;
     }
-    bool
+    [[nodiscard]] bool
     isStopping() const override
     {
         return false;
@@ -270,7 +279,7 @@ public:
     {
         throwUnimplemented();
     }
-    std::optional<uint256> const&
+    [[nodiscard]] std::optional<uint256> const&
     getTrapTxID() const override
     {
         static std::optional<uint256> const empty;
@@ -301,7 +310,7 @@ protected:
 TEST_F(MetricsRegistryTest, disabled_construction)
 {
     // Construct with enabled=false; should be a no-op.
-    telemetry::MetricsRegistry registry(false, mockApp_, j_);
+    telemetry::MetricsRegistry const registry(false, mockApp_, j_);
     EXPECT_FALSE(registry.isEnabled());
 }
 

src/xrpld/perflog/detail/PerfLogImp.cpp

@@ -383,9 +383,13 @@ PerfLogImp::rpcEnd(std::string const& method, std::uint64_t const requestId, boo
     if (auto* mr = app_.getMetricsRegistry())
     {
         if (finish)
+        {
             mr->recordRpcFinished(method, durationUs.count());
+        }
         else
+        {
             mr->recordRpcErrored(method, durationUs.count());
+        }
     }
 }
 

src/xrpld/telemetry/MetricsRegistry.cpp

@@ -21,6 +21,12 @@
 
 #include <xrpld/telemetry/MetricsRegistry.h>
 
+#include <xrpl/beast/utility/Journal.h>
+
+#include <cstdint>
+#include <string>
+#include <string_view>
+
 #ifdef XRPL_ENABLE_TELEMETRY
 
 #include <xrpld/app/ledger/AcceptedLedger.h>
@@ -62,8 +68,7 @@ namespace resource = opentelemetry::sdk::resource;
 
 #endif  // XRPL_ENABLE_TELEMETRY
 
-namespace xrpl {
-namespace telemetry {
+namespace xrpl::telemetry {
 
 MetricsRegistry::MetricsRegistry(
     [[maybe_unused]] bool enabled,
@@ -166,6 +171,8 @@ MetricsRegistry::start(std::string const& endpoint, std::string const& instanceI
     JLOG(journal_.info()) << "MetricsRegistry: started successfully";
 #else
     (void)endpoint;
+    (void)instanceId;
+    (void)enabled_;
 #endif  // XRPL_ENABLE_TELEMETRY
 }
 
@@ -202,6 +209,7 @@ MetricsRegistry::recordRpcStarted(std::string_view method)
     rpcStartedCounter_->Add(1, {{"method", std::string(method)}});
 #else
     (void)method;
+    (void)enabled_;
 #endif
 }
 
@@ -220,6 +228,7 @@ MetricsRegistry::recordRpcFinished(std::string_view method, std::int64_t duratio
 #else
     (void)method;
     (void)durationUs;
+    (void)enabled_;
 #endif
 }
 
@@ -238,6 +247,7 @@ MetricsRegistry::recordRpcErrored(std::string_view method, std::int64_t duration
 #else
     (void)method;
     (void)durationUs;
+    (void)enabled_;
 #endif
 }
 
@@ -254,6 +264,7 @@ MetricsRegistry::recordJobQueued(std::string_view jobType)
     jobQueuedCounter_->Add(1, {{"job_type", std::string(jobType)}});
 #else
     (void)jobType;
+    (void)enabled_;
 #endif
 }
 
@@ -272,6 +283,7 @@ MetricsRegistry::recordJobStarted(std::string_view jobType, std::int64_t queuedD
 #else
     (void)jobType;
     (void)queuedDurUs;
+    (void)enabled_;
 #endif
 }
 
@@ -290,6 +302,7 @@ MetricsRegistry::recordJobFinished(std::string_view jobType, std::int64_t runnin
 #else
     (void)jobType;
     (void)runningDurUs;
+    (void)enabled_;
 #endif
 }
 
@@ -1164,5 +1177,4 @@ MetricsRegistry::incrementJqTransOverflow()
 #endif
 }
 
-}  // namespace telemetry
-}  // namespace xrpl
+}  // namespace xrpl::telemetry