Fix zsh cross-compilation: --srcdir flag + awk permissions

Added --srcdir="${COOKBOOK_SOURCE}" to zsh configure flags to fix
the config.status error '/subs1.awk: Permission denied' during
cross-compilation. The error occurred because  was empty,
causing awk script paths to resolve to '/subs1.awk' instead of
the correct source directory path.

Also added chmod +x on Src/*.awk to ensure configure-generated
config.status can invoke awk scripts directly (autotools may try
to execute rather than interpret via awk -f).

This unblocks Phase 2.1 end-to-end build test.

recipes/shells/zsh/recipe.toml

@@ -18,6 +18,7 @@ script = """
 DYNAMIC_INIT
 
 COOKBOOK_CONFIGURE_FLAGS+=(
+    --srcdir="${COOKBOOK_SOURCE}"
     --disable-gdbm
     --disable-pcre
     --disable-cap
@@ -26,6 +27,10 @@ COOKBOOK_CONFIGURE_FLAGS+=(
 
 "${COOKBOOK_CONFIGURE}" "${COOKBOOK_CONFIGURE_FLAGS[@]}"
 
+# Ensure awk scripts are executable (cross-compilation fix for
+# config.status which tries to invoke awk scripts directly).
+chmod +x "${COOKBOOK_SOURCE}"/Src/*.awk 2>/dev/null || true
+
 # Pre-generate signames artifacts deterministically for Redox cross builds.
 gawk -f "${COOKBOOK_SOURCE}/Src/signames1.awk" "${COOKBOOK_ROOT}/prefix/${TARGET}/sysroot/${TARGET}/include/signal.h" > "${COOKBOOK_BUILD}/Src/sigtmp.c"
 "${COOKBOOK_ROOT}/bin/${TARGET}-gcc" -E -P "${COOKBOOK_BUILD}/Src/sigtmp.c" > "${COOKBOOK_BUILD}/Src/sigtmp.out"