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/rendering/terrain_manager.cpp

@@ -8,6 +8,7 @@
 #include "audio/ambient_sound_manager.hpp"
 #include "core/coordinates.hpp"
 #include "core/memory_monitor.hpp"
+#include "core/profiler.hpp"
 #include "pipeline/asset_manager.hpp"
 #include "pipeline/adt_loader.hpp"
 #include "pipeline/m2_loader.hpp"
@@ -188,6 +189,7 @@ bool TerrainManager::initialize(pipeline::AssetManager* assets, TerrainRenderer*
 }
 
 void TerrainManager::update(const Camera& camera, float deltaTime) {
+    ZoneScopedN("TerrainManager::update");
     if (!streamingEnabled || !assetManager || !terrainRenderer) {
         return;
     }
@@ -1236,6 +1238,7 @@ void TerrainManager::workerLoop() {
 }
 
 void TerrainManager::processReadyTiles() {
+    ZoneScopedN("TerrainManager::processReadyTiles");
     // Move newly ready tiles into the finalizing deque.
     // Keep them in pendingTiles so streamTiles() won't re-enqueue them.
     {