[Build] simplify src layer layout

AGENTS.md

@@ -15,7 +15,6 @@
   - `src/application`
   - `src/domain`
   - `src/engine`
-- Each layer may further split into `include/` and `src/` under its own root.
 - When touching build files, confirm that referenced source files are actually tracked in Git.
 
 ## Build
@@ -29,7 +28,8 @@
 
 ## Source Layout
 - All C++ source files live under `src/`.
-- Split each layer so headers live under `src/<layer>/include/<layer>/` and source files live under `src/<layer>/src/`.
+- Keep each layer's headers and source files directly under `src/<layer>/` unless a clear need for subfolders appears.
+- Use `src/` as the include root.
 - Preferred includes:
   - `#include "application/..."`
   - `#include "domain/..."`

CMakeLists.txt

@@ -32,33 +32,35 @@ function(configure_project_target target_name)
     set_property(TARGET ${target_name} PROPERTY VS_DEBUGGER_WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}")
 endfunction()
 
+set(SAFECROWD_SRC_DIR "${CMAKE_CURRENT_SOURCE_DIR}/src")
+
 add_library(ecs_engine STATIC
-    src/engine/include/engine/EngineConfig.h
-    src/engine/include/engine/EngineRuntime.h
-    src/engine/include/engine/EngineState.h
-    src/engine/include/engine/EngineStats.h
-    src/engine/include/engine/EngineStepContext.h
-    src/engine/include/engine/EngineSystem.h
-    src/engine/include/engine/FrameClock.h
-    src/engine/src/EngineRuntime.cpp
-    src/engine/src/FrameClock.cpp
+    src/engine/EngineConfig.h
+    src/engine/EngineRuntime.h
+    src/engine/EngineState.h
+    src/engine/EngineStats.h
+    src/engine/EngineStepContext.h
+    src/engine/EngineSystem.h
+    src/engine/FrameClock.h
+    src/engine/EngineRuntime.cpp
+    src/engine/FrameClock.cpp
 )
 
 target_include_directories(ecs_engine
     PUBLIC
-        ${CMAKE_CURRENT_SOURCE_DIR}/src/engine/include
+        ${SAFECROWD_SRC_DIR}
 )
 
 configure_project_target(ecs_engine)
 
 add_library(safecrowd_domain STATIC
-    src/domain/include/domain/SafeCrowdDomain.h
-    src/domain/src/SafeCrowdDomain.cpp
+    src/domain/SafeCrowdDomain.h
+    src/domain/SafeCrowdDomain.cpp
 )
 
 target_include_directories(safecrowd_domain
     PUBLIC
-        ${CMAKE_CURRENT_SOURCE_DIR}/src/domain/include
+        ${SAFECROWD_SRC_DIR}
 )
 
 target_link_libraries(safecrowd_domain
@@ -94,14 +96,14 @@ endif()
 
 if (SAFECROWD_BUILD_APP)
     add_executable(safecrowd_app
-        src/application/include/application/MainWindow.h
-        src/application/src/main.cpp
-        src/application/src/MainWindow.cpp
+        src/application/MainWindow.h
+        src/application/main.cpp
+        src/application/MainWindow.cpp
     )
 
     target_include_directories(safecrowd_app
         PRIVATE
-            ${CMAKE_CURRENT_SOURCE_DIR}/src/application/include
+            ${SAFECROWD_SRC_DIR}
     )
 
     set_target_properties(safecrowd_app PROPERTIES

docs/프로젝트 구조.md

@@ -44,14 +44,8 @@ Project/
   vcpkg.json
   src/
     engine/
-      include/engine/
-      src/
     domain/
-      include/domain/
-      src/
     application/
-      include/application/
-      src/
   external/
   docs/
 ```
@@ -180,12 +174,12 @@ Qt viewport가 엔진 렌더러와 직접 연결되어야 하면 `application ->
 
 ### 7.1. 소스 루트 원칙
 - 모든 C++ 소스와 헤더는 `src/` 아래에 둔다.
-- 각 계층은 `src/<layer>/include/<layer>/`에 헤더를, `src/<layer>/src/`에 구현 파일을 둔다.
+- 각 계층의 헤더와 구현 파일은 기본적으로 `src/<layer>/` 바로 아래에 둔다.
 - 따라서 include는 `#include "engine/..."`, `#include "domain/..."`, `#include "application/..."` 형태를 사용한다.
 
 ### 7.2. CMake 원칙
 - `CMakeLists.txt`의 타깃 소스 경로는 항상 `src/...`를 기준으로 적는다.
-- 각 타깃의 include directory는 해당 계층의 `src/<layer>/include/`를 공개 루트로 잡는다.
+- include directory는 `src/`를 공통 공개 루트로 잡는다.
 - 계층이 늘어나도 당분간 루트 `CMakeLists.txt` 하나에서 관리하고, 타깃 수와 파일 수가 커질 때만 하위 `CMakeLists.txt`를 추가한다.
 
 ### 7.3. 외부 의존성 원칙