feat(command-zone): add logic layer with tests

Implement CommandZoneLogic - the card data management layer for zones.
This layer handles card insertion, removal, and ordering independently
of Qt graphics rendering.

Key components:
- CommandZoneLogic: manages card data within a zone
- AddCardAlgorithm: generic insertion algorithm for ordered zones
- CardZoneLogic modifications: integrate with existing zone hierarchy

Design decisions:
- Separation of data logic from graphics enables unit testing
- addCardImpl uses a stable insertion algorithm for consistent ordering
- Mock card items enable testing without Qt graphics dependencies

Test coverage verifies card insertion behavior across edge cases.

tests/command_zone/CMakeLists.txt

@@ -10,6 +10,27 @@ set(TEST_QT_MODULES
     ${COCKATRICE_QT_VERSION_NAME}::Widgets
 )
 
+# ------------------------
+# Command Zone Logic Test
+# Tests addCardImpl insertion behavior
+# ------------------------
+add_executable(command_zone_logic_test
+    mocks/mock_card_item.cpp
+    command_zone_logic_test.cpp
+)
+
+target_include_directories(command_zone_logic_test
+    PRIVATE ${CMAKE_SOURCE_DIR}/cockatrice/src/game/zones/logic
+)
+
+target_link_libraries(command_zone_logic_test
+    PRIVATE Threads::Threads
+    PRIVATE ${GTEST_BOTH_LIBRARIES}
+    PRIVATE ${TEST_QT_MODULES}
+)
+
+add_test(NAME command_zone_logic_test COMMAND command_zone_logic_test)
+
 # ------------------------
 # Command Zone State Test
 # Tests the extracted CommandZoneState pure state machine
@@ -36,5 +57,6 @@ add_test(NAME command_zone_state_test COMMAND command_zone_state_test)
 # Dependencies on gtest
 # ------------------------
 if(NOT GTEST_FOUND)
+    add_dependencies(command_zone_logic_test gtest)
     add_dependencies(command_zone_state_test gtest)
 endif()