rsnix: preemptive kernel tasks (ADR 0003) — sched, IST fault stacks, 176-byte frames

- sched: 16-slot static table, shell=task 0, idle=task 1, spawn with
  guard page + 8 KiB stack, RR on the 100 Hz tick, int 0x60 yield,
  sleep_ms, lazy reap, jobs/bg/sleep/kill shell commands
- gdt: own GDT mirroring UEFI selectors + TSS with IST1/IST2
  (guard-page overflows die gracefully instead of triple-faulting)
- interrupts: isr_dispatch returns next frame in rax; IntFrame grows
  rsp/ss fields — QEMU's 64-bit iretq always pops all five slots from
  a 176-byte frame, so synthetic task frames must carry rsp=top+ss
  (a 160-byte frame made the first iretq pop rsp/ss from the unmapped
  page beyond the frame)
- panic handler: task panics abort the task, shell keeps running
- main: sched::init moved after page allocator + adopted tables
  (the idle's stack+guard need both; it was silently not spawning)

1 files changed, 1 insertions, 1 deletions

diff --git a/Cargo.toml b/Cargo.toml
index eb42b42..aab42e4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,7 +3,7 @@ resolver = "2"
 members = ["rsnix", "shell", "rsdos", "rsdosedit"]
 
 [workspace.package]
-version = "0.2.0"
+version = "0.3.0"
 edition = "2024"
 
 # no_std UEFI kernel: no unwinder available, so panic must abort.