Implemented multi-binary app packaging (#648)

Modules/app-module/CMakeLists.txt

@@ -9,6 +9,7 @@ tactility_add_module(app-module
     PRIV_INCLUDE_DIRS private/
     INCLUDE_DIRS include/
     REQUIRES TactilityKernel service-module minitar
+    PRIV_REQUIRES TactilityKernelCpp
 )
 
 # Tells source/io.cpp its real-syscall fallback must go through __real_read/write/close()
@@ -19,3 +20,11 @@ if (NOT APPLE)
     tactility_get_module_name(app-module MODULE_NAME)
     target_compile_definitions(${MODULE_NAME} PRIVATE TT_APP_IO_WRAPS_STDIO)
 endif ()
+
+# install.cpp resolves an installed binary's fixed bin/<platform>/<binary>.so path itself, so it
+# needs the same platform-arch string app-posix-module's own CMakeLists.txt defines for its
+# loader (the ESP32 equivalent, CONFIG_IDF_TARGET, comes for free from sdkconfig.h there).
+if (NOT ESP_PLATFORM)
+    tactility_get_module_name(app-module MODULE_NAME)
+    target_compile_definitions(${MODULE_NAME} PRIVATE "TACTILITY_POSIX_ARCH=\"${CMAKE_SYSTEM_PROCESSOR}\"")
+endif ()