refactor(build): merge vxcore_db into vxcore library

Eliminates separate vxcore_db library by merging DB sources directly into
vxcore. This fixes linker errors where sqlite_metadata_store.cpp couldn't
access file_utils symbols due to circular dependency between libraries.

- Move db/*.cpp sources into main vxcore library
- Update test_db and test_metadata_store to compile DB sources directly
- Remove src/db/CMakeLists.txt (no longer needed)

Author: tamlok

src/CMakeLists.txt

@@ -24,6 +24,11 @@ set(VXCORE_SOURCES
     core/folder.cpp
     core/bundled_folder_manager.cpp
     core/raw_folder_manager.cpp
+    db/db_manager.cpp
+    db/file_db.cpp
+    db/tag_db.cpp
+    db/sync_manager.cpp
+    db/sqlite_metadata_store.cpp
     search/search_manager.cpp
     search/search_query.cpp
     search/search_file_info.cpp
@@ -54,10 +59,7 @@ target_include_directories(vxcore
         ${CMAKE_SOURCE_DIR}/src
 )
 
-# Build database layer
-add_subdirectory(db)
-
-target_link_libraries(vxcore PRIVATE nlohmann_json vxcore_db)
+target_link_libraries(vxcore PRIVATE nlohmann_json sqlite3)
 
 if(WIN32)
     target_link_libraries(vxcore PRIVATE shell32)

src/db/CMakeLists.txt

@@ -36,13 +36,27 @@ target_include_directories(test_simple_search_backend PRIVATE ${CMAKE_SOURCE_DIR
 target_link_libraries(test_simple_search_backend PRIVATE nlohmann_json)
 add_test(NAME test_simple_search_backend COMMAND test_simple_search_backend)
 
-add_executable(test_db test_db.cpp ${CMAKE_SOURCE_DIR}/src/utils/logger.cpp)
+add_executable(test_db test_db.cpp
+    ${CMAKE_SOURCE_DIR}/src/db/db_manager.cpp
+    ${CMAKE_SOURCE_DIR}/src/db/file_db.cpp
+    ${CMAKE_SOURCE_DIR}/src/db/tag_db.cpp
+    ${CMAKE_SOURCE_DIR}/src/db/sync_manager.cpp
+    ${CMAKE_SOURCE_DIR}/src/core/folder.cpp
+    ${CMAKE_SOURCE_DIR}/src/utils/logger.cpp
+    ${CMAKE_SOURCE_DIR}/src/utils/file_utils.cpp
+    ${CMAKE_SOURCE_DIR}/src/utils/utils.cpp)
 target_include_directories(test_db PRIVATE ${CMAKE_SOURCE_DIR}/src ${CMAKE_SOURCE_DIR}/include ${CMAKE_SOURCE_DIR}/third_party)
-target_link_libraries(test_db PRIVATE vxcore vxcore_db sqlite3)
+target_link_libraries(test_db PRIVATE sqlite3 nlohmann_json)
 add_test(NAME test_db COMMAND test_db)
 
-add_executable(test_metadata_store test_metadata_store.cpp ${CMAKE_SOURCE_DIR}/src/utils/logger.cpp)
+add_executable(test_metadata_store test_metadata_store.cpp
+    ${CMAKE_SOURCE_DIR}/src/db/db_manager.cpp
+    ${CMAKE_SOURCE_DIR}/src/db/file_db.cpp
+    ${CMAKE_SOURCE_DIR}/src/db/tag_db.cpp
+    ${CMAKE_SOURCE_DIR}/src/db/sqlite_metadata_store.cpp
+    ${CMAKE_SOURCE_DIR}/src/utils/logger.cpp
+    ${CMAKE_SOURCE_DIR}/src/utils/file_utils.cpp)
 target_include_directories(test_metadata_store PRIVATE ${CMAKE_SOURCE_DIR}/src ${CMAKE_SOURCE_DIR}/include ${CMAKE_SOURCE_DIR}/third_party)
-target_link_libraries(test_metadata_store PRIVATE vxcore vxcore_db sqlite3)
+target_link_libraries(test_metadata_store PRIVATE sqlite3 nlohmann_json)
 add_test(NAME test_metadata_store COMMAND test_metadata_store)