feat(kernel): seL4-style IPC, notifications, status ABI

- badges + Mint, Call/Reply/ReplyRecv w/ gen-checked reply slot
- cap transfer (1/msg, copy, needs Delegate, rechecked at delivery)
- notifications: signal/wait/poll/bind, irq -> notification routing
- WaitAny/WaitForInterrupt removed; a0=status, ErrorCode
- libkos: single ecall primitive, compat wrappers + typed new api
- fix: trap return clobbered user t0 on every trap
- fix: wait queues FIFO, delegate keeps badge, fault cap checked
- docs/ipc.md spec, ipc tests, ipc fuzz, kani ntfn + waitqueue

crates/libkos/src/lib.rs

@@ -2,14 +2,14 @@
 
 extern crate alloc;
 
-mod arch;
-pub mod syscall;
 pub mod alloc_impl;
-pub mod io;
-pub mod fs;
+mod arch;
 pub mod display;
+pub mod fs;
 pub mod input;
+pub mod io;
 mod rt;
+pub mod syscall;
 
 #[cfg(target_os = "none")]
 #[global_allocator]