Adapter now: parses init binary (ELF or raw), allocates pages, creates
user page table, sets thread entry point in SavedContext, enters U-mode.
Init takes over from there — no more IPC demo hardcoded in the adapter.
- Halt syscall: only pid 0 (init) can halt, adapter uses SBI SRST
- Fault notification: kernel delivers fault info to process fault handler endpoint before killing
- Supervisor: tracks restart counts, back-off up to 5 restarts
- Shutdown: notifies servers, waits with timeout, calls halt
- Trap handler: faults now call kernel.handle_fault instead of halting
Add Priority::DEFAULT and TimeSlice::DEFAULT to types crate.
All QEMU virt addresses consolidated in board.rs.
Structure mirrors future adapter-arm/ layout.
