Add build modes and dev hooks, improve injection and docs

Introduces build mode options (rmfakecloud, qmldiff, dev, all) to CMake and build scripts, enabling selective compilation of hooks for cloud redirection, Qt resource hooking, and reverse engineering. Adds new hooks and memory logging for dev mode, updates injection script to handle libzstd.1.dylib dependency, and documents build modes in README.

CMakeLists.txt

@@ -6,6 +6,14 @@ enable_language(OBJC OBJCXX)
 set(CMAKE_C_STANDARD 11)
 set(CMAKE_CXX_STANDARD 17)
 
+# Build mode options
+# - rmfakecloud: Redirect reMarkable cloud to rmfakecloud server (default)
+# - qmldiff: Qt resource data registration hooking (WIP)
+# - dev: Development/reverse engineering mode with all hooks
+option(BUILD_MODE_RMFAKECLOUD "Build with rmfakecloud support" ON)
+option(BUILD_MODE_QMLDIFF "Build with QML diff/resource hooking" OFF)
+option(BUILD_MODE_DEV "Build with dev/reverse engineering hooks" OFF)
+
 # Compiler settings for macOS
 set(CMAKE_MACOSX_RPATH 1)
 set(CMAKE_OSX_DEPLOYMENT_TARGET "10.15" CACHE STRING "Minimum OS X deployment version")
@@ -93,8 +101,24 @@ set_target_properties(reMarkable PROPERTIES
 
 add_definitions(-DQT_NO_VERSION_TAGGING)
 
+# Add build mode compile definitions
+if(BUILD_MODE_RMFAKECLOUD)
+    target_compile_definitions(reMarkable PRIVATE BUILD_MODE_RMFAKECLOUD=1)
+    message(STATUS "Build mode: rmfakecloud (cloud redirection)")
+endif()
+
+if(BUILD_MODE_QMLDIFF)
+    target_compile_definitions(reMarkable PRIVATE BUILD_MODE_QMLDIFF=1)
+    message(STATUS "Build mode: qmldiff (resource hooking)")
+endif()
+
+if(BUILD_MODE_DEV)
+    target_compile_definitions(reMarkable PRIVATE BUILD_MODE_DEV=1)
+    message(STATUS "Build mode: dev (reverse engineering)")
+endif()
+
 target_link_libraries(reMarkable PRIVATE 
     ${LIBS}
     ${QT_LIB_TARGETS}
-    /opt/homebrew/Cellar/libzip/1.11.4/lib/intel/libzstd.1.5.7.dylib
+    ${PROJECT_ROOT_DIR}/libs/libzstd.1.dylib
 )