fix: fix login wallpaper startup delay

programs/include/montauk/syscall.h

@@ -191,6 +191,10 @@ namespace montauk {
 
     // Memory
     inline void* alloc(uint64_t size) { return (void*)syscall1(montauk::abi::SYS_ALLOC, size); }
+    // As alloc(), but the kernel commits the whole range immediately. Use it
+    // for a buffer that is about to be written end to end: the lazy path costs
+    // one page fault, one mutex acquire and one VMA walk per 4 KiB.
+    inline void* alloc_eager(uint64_t size) { return (void*)syscall1(montauk::abi::SYS_ALLOC_EAGER, size); }
     inline void free(void* ptr) { syscall1(montauk::abi::SYS_FREE, (uint64_t)ptr); }
 
     // Timekeeping