feat: unify system status codes

template/docs/syscalls.md

@@ -2,8 +2,31 @@
 
 All syscalls are available through `#include <montauk/syscall.h>` in the `montauk` namespace. The syscall layer provides `syscall0()` through `syscall6()` primitives using AMD64 calling conventions. All raw syscalls return `int64_t`.
 
+## Status Codes
+
+| Code | Value | Meaning |
+|------|-------|---------|
+| `Success` | 0 | The call succeeded |
+| `GenericFailure` | -1 | Unspecified failure |
+| `PermissionDenied` | -2 | The object belongs to another process or the handle lacks the right |
+| `CapabilityDenied` | -3 | The caller lacks (or was refused consent for) a required capability |
+| `SystemIntegrityError` | -4 | The path is protected (ProtectedPaths) and the caller may not modify it |
+| `BadPointer` | -5 | A user pointer or buffer range is invalid |
+| `InvalidArgument` | -6 | An argument, id, or handle is invalid |
+| `UnsupportedOp` | -7 | The operation is not supported here |
+| `NoDevice` | -8 | The required device is absent or not initialized |
+| `IoFailure` | -9 | Device I/O failed |
+| `BadInvocation` | -10 | Unknown syscall number |
+| `NoSuchPath` | -11 | The path does not exist |
+| `Busy` | -12 | The resource is in use or its queue is full |
+| `BufferTooSmall` | -13 | The output buffer is too small; retry with a larger one |
+| `OutOfMemory` | -14 | Memory could not be allocated |
+
+The Wi-Fi (`WIFI_ERR_*`) and USB (`USB_ERR_*`) syscalls keep their own error codes.
+
 ## Table of Contents
 
+- [Status Codes](#status-codes)
 - [Process Management](#process-management)
 - [File System](#file-system)
 - [Memory](#memory)