chore(testing): add unit tests and update core render/network pipelines

- add new tests:
  - test_blp_loader.cpp
  - test_dbc_loader.cpp
  - test_entity.cpp
  - test_frustum.cpp
  - test_m2_structs.cpp
  - test_opcode_table.cpp
  - test_packet.cpp
  - test_srp.cpp
  - CMakeLists.txt
- add docs and progress tracking:
  - TESTING.md
  - perf_baseline.md
- update project config/build:
  - .gitignore
  - CMakeLists.txt
  - test.sh
- core engine updates:
  - application.cpp
  - game_handler.cpp
  - world_socket.cpp
  - adt_loader.cpp
  - asset_manager.cpp
  - m2_renderer.cpp
  - post_process_pipeline.cpp
  - renderer.cpp
  - terrain_manager.cpp
  - game_screen.cpp
- add profiler header:
  - profiler.hpp

src/core/application.cpp

@@ -1,5 +1,6 @@
 #include "core/application.hpp"
 #include "core/coordinates.hpp"
+#include "core/profiler.hpp"
 #include <unordered_set>
 #include <cmath>
 #include <chrono>
@@ -569,6 +570,7 @@ bool Application::initialize() {
 }
 
 void Application::run() {
+    ZoneScopedN("Application::run");
     LOG_INFO("Starting main loop");
 
     // Pin main thread to a dedicated CPU core to reduce scheduling jitter
@@ -759,6 +761,7 @@ void Application::run() {
 
             // Update application state
             try {
+                FrameMark;
                 update(deltaTime);
             } catch (const std::bad_alloc& e) {
                 LOG_ERROR("OOM during Application::update (state=", static_cast<int>(state),
@@ -1110,6 +1113,7 @@ void Application::logoutToLogin() {
 }
 
 void Application::update(float deltaTime) {
+    ZoneScopedN("Application::update");
     const char* updateCheckpoint = "enter";
     try {
     // Update based on current state