fix(telemetry): fix CI failures — clang-tidy, levelization, linker

Clang-tidy fixes:
- Concatenate nested namespaces (modernize-concat-nested-namespaces)
  in OTelCollector.h, OTelCollector.cpp, ValidationTracker.h/.cpp
- Add missing direct includes (misc-include-cleaner) in
  ValidationTracker.cpp, test, CollectorManager.cpp, OTelCollector.cpp
- Make lock_guard variables const (misc-const-correctness)
- Add braces around single-line if/else (readability-braces-around-statements)
- Use designated initializer for WindowEvent (modernize-use-designated-initializers)
- Initialize LedgerEvent::seq field (cppcoreguidelines-pro-type-member-init)

Linker fix:
- Add ValidationTracker.cpp as source to xrpl.test.telemetry target
  (it lives in src/xrpld/ but the test links against libxrpl only)

Levelization fix:
- Remove stale dependency edges from ordering.txt that were introduced
  by the erroneous develop-merge commit

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

src/tests/libxrpl/CMakeLists.txt

@@ -46,6 +46,12 @@ endif()
 xrpl_add_test(telemetry)
 target_link_libraries(xrpl.test.telemetry PRIVATE xrpl.imports.test)
 target_include_directories(xrpl.test.telemetry PRIVATE ${CMAKE_SOURCE_DIR}/src)
+# ValidationTracker lives in src/xrpld/ (not libxrpl), so we compile its
+# implementation directly into the test binary.
+target_sources(
+    xrpl.test.telemetry
+    PRIVATE ${CMAKE_SOURCE_DIR}/src/xrpld/telemetry/detail/ValidationTracker.cpp
+)
 if(telemetry)
     target_link_libraries(
         xrpl.test.telemetry

src/tests/libxrpl/telemetry/ValidationTracker.cpp

@@ -4,9 +4,14 @@
 
 #include <xrpld/telemetry/ValidationTracker.h>
 
+#include <xrpl/basics/base_uint.h>
+#include <xrpl/protocol/Protocol.h>
+
 #include <gtest/gtest.h>
 
 #include <chrono>
+#include <cstddef>
+#include <cstdint>
 #include <thread>
 
 using namespace xrpl;