fix pi-lens warnings: unwraps, shell SC2046, dup code (fmtbuf/scripts/hexdump/cat/ahci/pci)

- memory.rs: self-test Layout::from_size_align no longer panics — the
  test fails cleanly on an invalid layout
- fat.rs: v() no longer unwraps the active-volume slot — invariant
  violation logs + halts instead of panicking mid-disk-io
- strbuf: shared FmtBuf replaces the duplicated PanicBuf/FmtBuf
  (main.rs + sched.rs)
- test-disk.sh: SC2046 — conditional --fresh arg no longer relies on
  word splitting
- scripts: boot.sh/boot-image.sh share lib-boot-args.sh (dup args loop)
- shell: cat/hexdump stdin pairs unified with Option<&str> marker;
  hexdump format_row folded into format_partial
- ahci: read/write_sectors unified behind dma_sectors
- pci: config_read/write share config_addr

1 files changed, 9 insertions, 3 deletions

diff --git a/rsnix/src/memory.rs b/rsnix/src/memory.rs
index 7c3eda0..e03af8b 100644
--- a/rsnix/src/memory.rs
+++ b/rsnix/src/memory.rs
@@ -458,7 +458,9 @@ pub fn self_test() -> bool {
             seed = seed.wrapping_mul(6364136223846793005).wrapping_add(1);
             let align = 16usize << (seed as usize % 8);
             seed = seed.wrapping_mul(6364136223846793005).wrapping_add(1);
-            let layout = Layout::from_size_align(size, align).unwrap();
+            let Ok(layout) = Layout::from_size_align(size, align) else {
+                return false; // impossible: size <= 2048, align <= 2048
+            };
             let p = ALLOCATOR.alloc(layout);
             if p.is_null() {
                 break; // heap exhausted — stop
@@ -493,7 +495,9 @@ pub fn self_test() -> bool {
             seed = seed.wrapping_mul(6364136223846793005).wrapping_add(1);
             let align = 16usize << (seed as usize % 8);
             seed = seed.wrapping_mul(6364136223846793005).wrapping_add(1);
-            let layout = Layout::from_size_align(size, align).unwrap();
+            let Ok(layout) = Layout::from_size_align(size, align) else {
+                return false; // impossible: size <= 2048, align <= 2048
+            };
             let p = ALLOCATOR.alloc(layout);
             if p.is_null() {
                 return false; // failed to reuse freed space
@@ -510,7 +514,9 @@ pub fn self_test() -> bool {
             if *ptr == 0 {
                 continue;
             }
-            let layout = Layout::from_size_align(*size, *align).unwrap();
+            let Ok(layout) = Layout::from_size_align(*size, *align) else {
+                return false; // impossible: sizes/aligns came from the loop above
+            };
             ALLOCATOR.dealloc(*ptr as *mut u8, layout);
         }
         let stats = heap_stats();