Bump workspace to edition 2024

- edition = "2024" in the workspace manifest and rsdosedit
- extern blocks must be unsafe: interrupts.rs ISR stubs -> unsafe extern "C"
- #[no_mangle] -> #[unsafe(no_mangle)] (efi_main, isr_dispatch)
- One missed static-mut read in free_list_insert wrapped in an explicit
  unsafe block (edition 2024 removed the implicit unsafe context inside
  unsafe fns)
- rustfmt reflows for 2024: nested if-lets become let-chains, imports
  re-sorted, rsdosedit help-screen box rows wrapped

No codegen-affecting changes. Validated: cargo check/clippy/fmt clean
(host + uefi target), make test-disk PASS, editor round-trip PASS.

1 files changed, 1 insertions, 1 deletions

diff --git a/rsnix/src/paging.rs b/rsnix/src/paging.rs
index 766bde3..d786dee 100644
--- a/rsnix/src/paging.rs
+++ b/rsnix/src/paging.rs
@@ -12,7 +12,7 @@
 // refcounting) — fine for a kernel that owns all memory.
 // ---------------------------------------------------------------------------
 
-use crate::memory::{alloc_pages, free_pages, PAGE_SIZE};
+use crate::memory::{PAGE_SIZE, alloc_pages, free_pages};
 
 pub const PAGE_PRESENT: u64 = 1 << 0;
 pub const PAGE_WRITABLE: u64 = 1 << 1;