Refactor SDL/FreeRTOS implementation to support macOS simulator properly (#653)

- Run SDL from main() and place FreeRTOS in separate thread. This fixes macOS support.
- Updated GitHub Actions to publish macOS simulator build for testing, updated amd64 to x86_64 for consistent naming.

Modules/app-module/CMakeLists.txt

@@ -10,15 +10,29 @@ tactility_add_module(app-module
     INCLUDE_DIRS include/
     REQUIRES TactilityKernel service-module minitar
     PRIV_REQUIRES TactilityKernelCpp
+    WHOLE_ARCHIVE
 )
 
-# Tells source/io.cpp its real-syscall fallback must go through __real_read/write/close()
-# rather than calling ::read/::write/::close() directly, on every platform whose build wraps
-# those symbols (ESP-IDF always; POSIX except macOS, whose linker doesn't support --wrap) -
-# see Tactility/CMakeLists.txt and the top-level CMakeLists.txt for where that's applied.
-if (NOT APPLE)
+# Tells source/io.cpp its real-syscall fallback must go through __real_read/write/close() rather
+# than calling ::read/::write/::close() directly, on every platform where those are wrapped: via
+# -Wl,--wrap= on ESP-IDF (see the top-level CMakeLists.txt) and non-Apple POSIX (below), or via
+# source/stdio_wrap.cpp's dyld interpose on Apple (whose linker lacks --wrap).
+tactility_get_module_name(app-module MODULE_NAME)
+target_compile_definitions(${MODULE_NAME} PRIVATE TT_APP_IO_WRAPS_STDIO)
+
+# Routes every read()/write()/close() and printf-family call to source/stdio_wrap.cpp's __wrap_*
+# functions; see that file for what they do and why. ESP-IDF wraps the same symbols itself (see
+# the top-level CMakeLists.txt); Apple gets the same routing via dyld interpose instead, self-
+# registered in that file. PUBLIC so every consumer of this module (Tactility, and any test target
+# that links app-module directly) gets the flags too.
+if (NOT ESP_PLATFORM AND NOT APPLE)
     tactility_get_module_name(app-module MODULE_NAME)
-    target_compile_definitions(${MODULE_NAME} PRIVATE TT_APP_IO_WRAPS_STDIO)
+    target_link_options(${MODULE_NAME} PUBLIC
+        "-Wl,--wrap=read" "-Wl,--wrap=write" "-Wl,--wrap=close"
+        "-Wl,--wrap=printf" "-Wl,--wrap=fprintf" "-Wl,--wrap=vprintf" "-Wl,--wrap=vfprintf"
+        "-Wl,--wrap=puts" "-Wl,--wrap=fputs" "-Wl,--wrap=putchar" "-Wl,--wrap=fputc"
+        "-Wl,--wrap=getchar" "-Wl,--wrap=fgetc" "-Wl,--wrap=fgets"
+    )
 endif ()
 
 # install.cpp resolves an installed binary's fixed bin/<platform>/<binary>.so path itself, so it