feat: extend wasm backend entrypoints

src/lib/sys.cpp

@@ -318,6 +318,10 @@ StringMap default_config()
 #include "sys.h"
 #include "hash.h"
 
+// Single definitions for the native split build (declared extern in sys.h).
+pid_t parent_pid = 0;
+pid_t my_pid = 0;
+
 namespace {
 
 constexpr f64 FILE_LOCK_WAIT_TIMEOUT_SECONDS = 3.0;