Fix all clippy warnings: dead code, match patterns, type complexity, docs

- Remove unused pes_buf field from M2tsStream and unused TS_PACKET/BD_TS_PACKET constants
- Replace match-with-single-pattern with if let (3 instances in drive/mod.rs)
- Replace match-can-be-? with ? operator for scsi::open call
- Add type aliases PesSetup and MkvHeaderResult to reduce type complexity
- Collapse identical if/else branches in tsmux.rs build_pes_header
- Use RangeInclusive::contains instead of manual range checks
- Make WriteSeek trait pub (was pub(crate) but leaked through pub fn)
- Remove empty line after doc comment in disc.rs
- Fix doc list item indentation in scsi/linux.rs (12 instances)

src/mux/disc.rs

@@ -166,7 +166,6 @@ impl DiscStream {
     }
 
     /// Set SCSI read timeout (default 30s).
-
     fn new(drive: Drive, title: DiscTitle, mode: ReadMode, max_batch: u16) -> Self {
         // Set up PES demux from title stream PIDs
         let mut pids = Vec::new();

src/mux/m2ts.rs

@@ -7,6 +7,8 @@ use super::{meta, ts, IOStream, ReadSeek};
 use crate::disc::{DiscTitle, Stream as DiscStream};
 use std::io::{self, Read, Seek, SeekFrom, Write};
 
+type PesSetup = (Vec<u16>, Vec<(u16, Box<dyn super::codec::CodecParser>)>, Vec<(u16, usize)>);
+
 /// Size of initial scan buffer for PMT/stream detection.
 const SCAN_SIZE: usize = 1024 * 1024;
 
@@ -32,7 +34,6 @@ pub struct M2tsStream {
     parsers: Vec<(u16, Box<dyn super::codec::CodecParser>)>,
     pending_frames: std::collections::VecDeque<crate::pes::PesFrame>,
     pid_to_track: Vec<(u16, usize)>,
-    pes_buf: Vec<u8>,
     pes_eof: bool,
 }
 
@@ -51,12 +52,11 @@ impl M2tsStream {
             parsers: Vec::new(),
             pending_frames: std::collections::VecDeque::new(),
             pid_to_track: Vec::new(),
-            pes_buf: Vec::new(),
             pes_eof: false,
         }
     }
 
-    fn setup_pes(streams: &[DiscStream]) -> (Vec<u16>, Vec<(u16, Box<dyn super::codec::CodecParser>)>, Vec<(u16, usize)>) {
+    fn setup_pes(streams: &[DiscStream]) -> PesSetup {
         let mut pids = Vec::new();
         let mut parsers: Vec<(u16, Box<dyn super::codec::CodecParser>)> = Vec::new();
         let mut pid_to_track = Vec::new();
@@ -104,7 +104,6 @@ impl M2tsStream {
                 parsers,
                 pending_frames: std::collections::VecDeque::new(),
                 pid_to_track,
-                pes_buf: vec![0u8; 192 * 1024],
                 pes_eof: false,
             });
         }
@@ -144,7 +143,6 @@ impl M2tsStream {
             parsers,
             pending_frames: std::collections::VecDeque::new(),
             pid_to_track,
-            pes_buf: vec![0u8; 192 * 1024],
             pes_eof: false,
         })
     }

src/mux/mkvstream.rs

@@ -8,6 +8,8 @@ use super::lookahead::{LookaheadBuffer, LookaheadState, DEFAULT_LOOKAHEAD_SIZE};
 use super::mkv::{MkvMuxer, MkvTrack};
 use super::ts::TsDemuxer;
 use super::{ebml, IOStream, ReadSeek, WriteSeek};
+
+type MkvHeaderResult = io::Result<(crate::disc::DiscTitle, Vec<(u16, Vec<u8>)>)>;
 use crate::disc::*;
 use std::io::{self, Read, Seek, SeekFrom, Write};
 
@@ -462,7 +464,7 @@ fn write_pes(
 /// Returns (DiscTitle, codec_privates: Vec<(track_number, codec_private_bytes)>)
 fn parse_mkv_header(
     r: &mut (impl Read + Seek),
-) -> io::Result<(DiscTitle, Vec<(u16, Vec<u8>)>)> {
+) -> MkvHeaderResult {
     let mut title = String::new();
     let mut duration_ms = 0.0f64;
     let mut ts_scale: u64 = 1_000_000;

src/mux/mod.rs

@@ -79,5 +79,5 @@ pub trait IOStream: Read + Write {
 pub(crate) trait ReadSeek: Read + Seek {}
 impl<T: Read + Seek> ReadSeek for T {}
 
-pub(crate) trait WriteSeek: Write + Seek {}
+pub trait WriteSeek: Write + Seek {}
 impl<T: Write + Seek> WriteSeek for T {}

src/mux/tsmux.rs

@@ -8,8 +8,6 @@ use std::io::{self, Write};
 
 const SYNC_BYTE: u8 = 0x47;
 const TS_PAYLOAD: usize = 184;
-const TS_PACKET: usize = 188;
-const BD_TS_PACKET: usize = 192;
 
 pub struct TsMuxer<W: Write> {
     writer: W,
@@ -112,14 +110,10 @@ impl<W: Write> TsMuxer<W> {
 /// Build a PES packet header for a BD stream.
 fn build_pes_header(pid: u16, pts_90k: u64, data_len: usize) -> Vec<u8> {
     // Determine stream_id from PID range
-    let stream_id: u8 = if pid >= 0x1011 && pid <= 0x101F {
+    let stream_id: u8 = if (0x1011..=0x101F).contains(&pid) {
         0xE0 // video
-    } else if pid >= 0x1100 && pid <= 0x111F {
-        0xBD // audio (private stream 1)
-    } else if pid >= 0x1200 && pid <= 0x121F {
-        0xBD // PGS subtitle
     } else {
-        0xBD // default
+        0xBD // audio, PGS subtitle, or default (private stream 1)
     };
 
     let pes_data_len = data_len + 8; // 3 header bytes + 5 PTS bytes + data