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

tests/test_frustum.cpp

@@ -0,0 +1,132 @@
+// Phase 0 – Frustum plane extraction and intersection tests
+#include <catch_amalgamated.hpp>
+#include "rendering/frustum.hpp"
+
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+
+using wowee::rendering::Frustum;
+using wowee::rendering::Plane;
+
+TEST_CASE("Plane distanceToPoint", "[frustum]") {
+    // Plane facing +Y at y=5
+    Plane p(glm::vec3(0.0f, 1.0f, 0.0f), -5.0f);
+
+    // Point at y=10 → distance = 10 + (-5) = 5 (in front)
+    REQUIRE(p.distanceToPoint(glm::vec3(0, 10, 0)) == Catch::Approx(5.0f));
+
+    // Point at y=5 → distance = 0 (on plane)
+    REQUIRE(p.distanceToPoint(glm::vec3(0, 5, 0)) == Catch::Approx(0.0f));
+
+    // Point at y=0 → distance = -5 (behind)
+    REQUIRE(p.distanceToPoint(glm::vec3(0, 0, 0)) == Catch::Approx(-5.0f));
+}
+
+TEST_CASE("Frustum extractFromMatrix with identity", "[frustum]") {
+    Frustum f;
+    f.extractFromMatrix(glm::mat4(1.0f));
+
+    // Identity matrix gives clip-space frustum: [-1,1]^3 (or [0,1] for z)
+    // The origin should be inside
+    REQUIRE(f.containsPoint(glm::vec3(0.0f, 0.0f, 0.5f)));
+}
+
+TEST_CASE("Frustum containsPoint perspective", "[frustum]") {
+    // Create a typical perspective projection and look-at
+    glm::mat4 proj = glm::perspective(glm::radians(90.0f), 1.0f, 0.1f, 100.0f);
+    glm::mat4 view = glm::lookAt(
+        glm::vec3(0, 0, 0),   // eye
+        glm::vec3(0, 0, -1),  // center (looking -Z)
+        glm::vec3(0, 1, 0)    // up
+    );
+    glm::mat4 vp = proj * view;
+
+    Frustum f;
+    f.extractFromMatrix(vp);
+
+    // Point in front (at -Z)
+    REQUIRE(f.containsPoint(glm::vec3(0, 0, -10)));
+
+    // Point behind camera (at +Z) should be outside
+    REQUIRE_FALSE(f.containsPoint(glm::vec3(0, 0, 10)));
+
+    // Point very far away inside the frustum
+    REQUIRE(f.containsPoint(glm::vec3(0, 0, -50)));
+
+    // Point beyond far plane
+    REQUIRE_FALSE(f.containsPoint(glm::vec3(0, 0, -200)));
+}
+
+TEST_CASE("Frustum intersectsSphere", "[frustum]") {
+    glm::mat4 proj = glm::perspective(glm::radians(60.0f), 1.0f, 1.0f, 100.0f);
+    glm::mat4 view = glm::lookAt(
+        glm::vec3(0, 0, 0),
+        glm::vec3(0, 0, -1),
+        glm::vec3(0, 1, 0)
+    );
+    Frustum f;
+    f.extractFromMatrix(proj * view);
+
+    // Sphere clearly inside
+    REQUIRE(f.intersectsSphere(glm::vec3(0, 0, -10), 1.0f));
+
+    // Sphere behind camera
+    REQUIRE_FALSE(f.intersectsSphere(glm::vec3(0, 0, 50), 1.0f));
+
+    // Large sphere that straddles the near plane
+    REQUIRE(f.intersectsSphere(glm::vec3(0, 0, 0), 5.0f));
+
+    // Sphere at edge of frustum — large radius should still intersect
+    REQUIRE(f.intersectsSphere(glm::vec3(0, 0, -105), 10.0f));
+}
+
+TEST_CASE("Frustum intersectsAABB", "[frustum]") {
+    glm::mat4 proj = glm::perspective(glm::radians(60.0f), 1.0f, 1.0f, 100.0f);
+    glm::mat4 view = glm::lookAt(
+        glm::vec3(0, 0, 0),
+        glm::vec3(0, 0, -1),
+        glm::vec3(0, 1, 0)
+    );
+    Frustum f;
+    f.extractFromMatrix(proj * view);
+
+    // Box inside frustum
+    REQUIRE(f.intersectsAABB(glm::vec3(-1, -1, -11), glm::vec3(1, 1, -9)));
+
+    // Box behind camera
+    REQUIRE_FALSE(f.intersectsAABB(glm::vec3(-1, -1, 5), glm::vec3(1, 1, 10)));
+
+    // Box beyond far plane
+    REQUIRE_FALSE(f.intersectsAABB(glm::vec3(-1, -1, -200), glm::vec3(1, 1, -150)));
+
+    // Large box straddling near/far
+    REQUIRE(f.intersectsAABB(glm::vec3(-5, -5, -50), glm::vec3(5, 5, 0)));
+}
+
+TEST_CASE("Frustum getPlane returns 6 planes", "[frustum]") {
+    glm::mat4 proj = glm::perspective(glm::radians(90.0f), 1.0f, 1.0f, 100.0f);
+    Frustum f;
+    f.extractFromMatrix(proj);
+
+    // Access all 6 planes — should not crash
+    for (int i = 0; i < 6; ++i) {
+        const auto& p = f.getPlane(static_cast<Frustum::Side>(i));
+        // Normal should be a unit vector (after normalization)
+        float len = glm::length(p.normal);
+        REQUIRE(len == Catch::Approx(1.0f).margin(0.01f));
+    }
+}
+
+TEST_CASE("Frustum box far right is outside", "[frustum]") {
+    glm::mat4 proj = glm::perspective(glm::radians(45.0f), 1.0f, 1.0f, 100.0f);
+    glm::mat4 view = glm::lookAt(
+        glm::vec3(0, 0, 0),
+        glm::vec3(0, 0, -1),
+        glm::vec3(0, 1, 0)
+    );
+    Frustum f;
+    f.extractFromMatrix(proj * view);
+
+    // Box far off to the right — outside the frustum
+    REQUIRE_FALSE(f.intersectsAABB(glm::vec3(200, 0, -10), glm::vec3(201, 1, -9)));
+}