Audit fixes + DVD support foundation (IFO, PS demux, MPEG-2, CSS crack)

Audit fixes (14 critical, 22 warnings):
- UDF: bounds checks on all ICB/FID parsing from disc data
- SCSI Linux: saturating_sub on residual, CDB length guard, buffer size guard
- SCSI macOS: SCSITaskStatus u32 (was u8 — stack corruption)
- AACS: EC mod_inv returns infinity instead of panic, key reduced mod n
- AACS: do_handshake tries all host certs (was returning on first failure)
- H.264: bounds check on SPS < 4 bytes
- ContentReader: error on missing unit key (was zero-fill)
- KEYDB: flat redirect loop (was recursive), 100MB response limit, Windows HOME fallback
- ISO writer: AVDP extent order, partition length, allocation cap
- Network: removed TCP_NODELAY on bulk stream
- MKV: guard on u64::MAX seek
- disc.rs: saturating_sub on extent offset, simplified dead region code
- cargo fmt (610 violations), cargo clippy --fix (55 auto-fixes)

DVD support (new files):
- src/ifo.rs — IFO parser (VIDEO_TS.IFO, VTS_XX_0.IFO, PGC chains, cells, streams) — 13 tests
- src/mux/ps.rs — MPEG-2 Program Stream demuxer (pack headers, PES, private stream 1) — 12 tests
- src/mux/codec/mpeg2.rs — MPEG-2 video parser (sequence headers, I-frame detection) — 15 tests
- src/css/crack.rs — split-attack algorithm (LFSR cipher needs verification — test ignored)

226 tests total (was 186), 1 ignored (CSS crack needs cipher verification).

src/scsi/windows.rs

@@ -5,8 +5,8 @@
 //!
 //! Requires administrator privileges for raw SCSI access.
 
-use crate::error::{Error, Result};
 use super::{DataDirection, ScsiResult, ScsiTransport};
+use crate::error::{Error, Result};
 use std::path::Path;
 
 // ── Windows constants ──────────────────────────────────────────────────────
@@ -89,7 +89,9 @@ pub struct SptiTransport {
 
 /// Normalize a device path to Windows \\.\X: format.
 fn normalize_device_path(path: &str) -> String {
-    if path.starts_with("\\\\.\\") { return path.to_string(); }
+    if path.starts_with("\\\\.\\") {
+        return path.to_string();
+    }
     let trimmed = path.trim_end_matches('\\');
     if trimmed.len() == 2 && trimmed.as_bytes()[1] == b':' {
         return format!("\\\\.\\{}", trimmed);
@@ -134,7 +136,9 @@ impl SptiTransport {
 
 impl Drop for SptiTransport {
     fn drop(&mut self) {
-        unsafe { CloseHandle(self.handle); }
+        unsafe {
+            CloseHandle(self.handle);
+        }
     }
 }
 
@@ -159,7 +163,11 @@ impl ScsiTransport for SptiTransport {
         };
         sptwb.spt.DataTransferLength = data.len() as u32;
         sptwb.spt.TimeOutValue = (timeout_ms / 1000).max(1) as u32;
-        sptwb.spt.DataBuffer = if data.is_empty() { std::ptr::null_mut() } else { data.as_mut_ptr() };
+        sptwb.spt.DataBuffer = if data.is_empty() {
+            std::ptr::null_mut()
+        } else {
+            data.as_mut_ptr()
+        };
         sptwb.spt.SenseInfoOffset = std::mem::offset_of!(SptwbDirect, sense) as u32;
         sptwb.spt.Cdb[..cdb_len].copy_from_slice(&cdb[..cdb_len]);
 
@@ -188,7 +196,11 @@ impl ScsiTransport for SptiTransport {
         }
 
         if sptwb.spt.ScsiStatus != 0 {
-            let sense_key = if sptwb.sense[2] != 0 { sptwb.sense[2] & 0x0F } else { 0 };
+            let sense_key = if sptwb.sense[2] != 0 {
+                sptwb.sense[2] & 0x0F
+            } else {
+                0
+            };
             return Err(Error::ScsiError {
                 opcode: cdb[0],
                 status: sptwb.spt.ScsiStatus,
@@ -206,4 +218,3 @@ impl ScsiTransport for SptiTransport {
         })
     }
 }
-