feat: extend wasm backend entrypoints

src/lib/sys.h

@@ -100,8 +100,15 @@ bool memcache_delete(u64 connection, String key);
 String memcache_get(u64 connection, String key, String default_value = "");
 StringMap memcache_get_multiple(u64 connection, StringList keys);
 
+// Defined once in sys.cpp for the native split build (core/wasm/main); the wasm
+// core/unit builds keep the in-place definition (single TU / loader-resolved).
+#if defined(__UCE_WASM_CORE__) || defined(__UCE_WASM_UNIT__)
 pid_t parent_pid = 0;
 pid_t my_pid = 0;
+#else
+extern pid_t parent_pid;
+extern pid_t my_pid;
+#endif
 
 void on_segfault(int sig);
 int task_kill(pid_t pid, int sig = 0);