Refresh Qt integration tooling

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

local/recipes/qt/redox-toolchain.cmake

@@ -124,12 +124,12 @@ set(CMAKE_PLATFORM_USES_PATH_WHEN_NO_SONAME 1)
 # --- Redox POSIX compatibility shims ---
 # relibc's assert.h does not define static_assert (C11 macro). Provide it for C only
 # (C++ has it as a keyword — redefining would cause errors in try_compile checks).
-# Also provide waitid() idtype constants P_PID, P_PGID, P_ALL (missing from relibc).
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Dstatic_assert=_Static_assert -DP_ALL=0 -DP_PID=1 -DP_PGID=2 -Dvfork=fork" CACHE STRING "")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DP_ALL=0 -DP_PID=1 -DP_PGID=2 -Dvfork=fork" CACHE STRING "")
 
-# relibc lacks waitid() — the stub is injected directly into Qt's Core library via
-# target_sources() in the qtbase recipe. No linker flags needed here.
+# relibc now provides waitid() itself, but qtbase/forkfd still does not reliably pick up the
+# P_PID / P_PGID / P_ALL constants through the active cross-build include path, so keep the
+# constants forced here until the downstream build proves them redundant.
 
 # --- Qt6 cross-compilation helpers ---
 # QT_MKSPECS_DIR: Qt6's QtMkspecHelpers.cmake sets this from QT_SOURCE_TREE,

local/recipes/qt/redox_waitid.c

@@ -1,13 +0,0 @@
-/* Redox POSIX compat: waitid() stub for relibc.
-   relibc has waitpid() but waitid() is unimplemented (commented out).
-   Qt's forkfd.c calls waitid(P_PID, ...) for child readiness checks.
-   Returning -1 (no children ready) is safe — fork() still works for process spawning. */
-#include <signal.h>
-
-int waitid(int idtype, int id, siginfo_t *info, int options) {
-    (void)idtype;
-    (void)id;
-    (void)info;
-    (void)options;
-    return -1;
-}