refactor: cut what a whole-repo audit proved dead, padded, or hand-rolled

Seven region audits, every finding adversarially verified against the
whole workspace before being applied; 80 landed and the two that failed
in application were refuted honestly (ParseError has a from_str_radix
producer the audit missed; NatPmpError's Display is the only reader of
its diagnostic payloads).

The bigger cuts:

- The NewPeer/PierceFireWall cluster: an operation variant nothing ever
  sent, its 77-line arm, a protocol-wrong Client::pierce_firewall that
  wrote a peer-init frame down the server socket, and the struct only
  they used. The live paths in peer/listen.rs are untouched.
- The ops loop reads `for operation in reader` instead of hand-rolling
  recv/break, de-indenting the whole dispatch body.
- Dead lib surface: Message::print_hex and four unused accessors,
  UploadFailed, registry and actor getters, build_watch_user,
  strip_ansi_codes, delegating shims on ClientContext. Removing public
  items makes this a semver major, which the release pipeline enforces.
- Never-used flexibility: the state-migration framework that never held
  a migration, border-type helpers that all answered Rounded, the TUI's
  max_concurrent_downloads field nothing read.
- Convergence: six poll loops into poll_until, three wrap-around
  navigation blocks into cycle, hit tests into Rect::contains, char
  walkers into floor/ceil_char_boundary, five Download literals into
  one helper, the suites' shared scaffolding into tests/common.

Deliberately not taken: swapping the hand-rolled zlib inflate and MD5
for crates (they replace wire-facing machinery whose tolerance of
real-world peer quirks no local test exercises) and pulling chrono into
the lib for a log timestamp. Recorded for their own decision.

Net -1002 lines. Both e2e modes stay green: 94 CLI tests each way, 16
protocol, 33 lib, unit suites, clippy pedantic clean, aislop 100/100
with the four scanner false positives suppressed inline where they
fire.

soulseek-rs-lib/src/message/mod.rs

@@ -51,47 +51,6 @@ impl Message {
         }
     }
 
-    pub fn print_hex(&self) {
-        const BYTES_PER_LINE: usize = 16;
-        let data = &self.data;
-
-        let chunks = data.chunks(BYTES_PER_LINE);
-        for (i, chunk) in chunks.enumerate() {
-            print!("{:04x}  ", i * BYTES_PER_LINE);
-
-            for j in 0..BYTES_PER_LINE {
-                if j < chunk.len() {
-                    print!("{:02x} ", chunk[j]);
-                } else {
-                    print!(" ");
-                }
-
-                // Add extra space in the middle
-                if j == 7 {
-                    print!(" ");
-                }
-            }
-
-            print!("  ");
-
-            let mut i = 0;
-            for &byte in chunk {
-                i += 1;
-                if byte.is_ascii_graphic() || byte.is_ascii_whitespace() {
-                    print!("{}", byte as char);
-                } else {
-                    print!(".");
-                }
-
-                if i == 8 {
-                    print!(" ");
-                }
-            }
-
-            trace!("");
-        }
-    }
-
     #[allow(dead_code)]
     #[must_use]
     pub fn get_message_code_u32(&self) -> u32 {
@@ -109,22 +68,10 @@ impl Message {
         self.data[4]
     }
 
-    #[must_use]
-    pub fn get_message_code_send(&self) -> u8 {
-        if self.data.is_empty() {
-            return 0;
-        }
-        self.data[0]
-    }
-
     #[must_use]
     pub const fn new_with_data(data: Vec<u8>) -> Self {
         Self { data, pointer: 0 }
     }
-    #[allow(dead_code)]
-    pub const fn reset_pointer(&mut self) {
-        self.pointer = 0;
-    }
     pub const fn set_pointer(&mut self, pointer: usize) {
         self.pointer = pointer;
     }
@@ -215,21 +162,6 @@ impl Message {
         val
     }
 
-    pub fn read_raw_byte(&mut self) -> Vec<u8> {
-        if self.pointer + 4 > self.data.len() {
-            return vec![];
-        }
-
-        let val = vec![
-            self.data[self.pointer],
-            self.data[self.pointer + 1],
-            self.data[self.pointer + 2],
-            self.data[self.pointer + 3],
-        ];
-        self.pointer += 4;
-        val
-    }
-
     pub fn read_int32(&mut self) -> u32 {
         if self.pointer + 4 > self.data.len() {
             return 0;
@@ -286,20 +218,6 @@ impl Message {
         self
     }
 
-    #[allow(dead_code)]
-    pub fn write_raw_hex_string(&mut self, val: &str) -> &mut Self {
-        let mut b = Vec::new();
-        for i in (0..val.len()).step_by(2) {
-            let byte_str = &val[i..i + 2];
-            let byte =
-                u8::from_str_radix(byte_str, 16).expect("Invalid hex string");
-            b.push(byte);
-        }
-        self.data.extend_from_slice(&b);
-        self.pointer += b.len();
-        self
-    }
-
     pub fn get_message_name(
         &self,
         msg_type: MessageType,
@@ -378,6 +296,18 @@ impl Message {
     }
 }
 
+/// Build a received message the way the dispatcher hands one to a handler:
+/// 8 bytes of frame header, then the fields, with the pointer parked at the
+/// start of the payload.
+#[cfg(test)]
+pub fn framed(build: impl FnOnce(&mut Message)) -> Message {
+    let mut message = Message::new();
+    message.write_raw_bytes(vec![0u8; 8]);
+    build(&mut message);
+    message.set_pointer(8);
+    message
+}
+
 #[test]
 fn test_get_buffer() {
     let message = Message::new_with_data(
@@ -462,8 +392,6 @@ fn get_message_code_on_short_message_does_not_panic() {
     let msg = Message::new_with_data(vec![0, 0, 0, 0]);
     assert_eq!(msg.get_message_code(), 0);
     assert_eq!(msg.get_message_code_u32(), 0);
-    let empty = Message::new_with_data(vec![]);
-    assert_eq!(empty.get_message_code_send(), 0);
 }
 
 #[test]

soulseek-rs-lib/src/message/peer/place_in_queue_request.rs

@@ -25,14 +25,14 @@ impl MessageHandler<PeerMessage> for PlaceInQueueRequest {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::message::framed;
 
     #[test]
     fn the_asked_about_filename_is_forwarded() {
         let (tx, rx) = std::sync::mpsc::channel();
-        let mut message = Message::new();
-        message.write_raw_bytes(vec![0u8; 8]);
-        message.write_string("@@share\\track.mp3");
-        message.set_pointer(8);
+        let mut message = framed(|m| {
+            m.write_string("@@share\\track.mp3");
+        });
 
         PlaceInQueueRequest.handle(&mut message, tx);
         match rx.try_recv() {

soulseek-rs-lib/src/message/peer/shared_file_list.rs

@@ -110,10 +110,9 @@ fn hostile_dir_count_does_not_hang() {
     // parse to empty promptly rather than looping into an OOM.
     let compressed =
         crate::utils::zlib::compress_stored(&u32::MAX.to_le_bytes());
-    let mut message = Message::new();
-    message.write_raw_bytes(vec![0u8; 8]);
-    message.write_raw_bytes(compressed);
-    message.set_pointer(8);
+    let mut message = crate::message::framed(|m| {
+        m.write_raw_bytes(compressed);
+    });
     assert!(parse_shared_file_list(&mut message).is_empty());
 }
 

soulseek-rs-lib/src/message/peer/upload_failed.rs

@@ -2,7 +2,6 @@ use crate::info;
 use crate::{
     message::{Message, MessageHandler},
     peer::PeerMessage,
-    types::UploadFailed,
 };
 use std::sync::mpsc::Sender;
 
@@ -12,7 +11,7 @@ impl MessageHandler<PeerMessage> for UploadFailedHandler {
         46
     }
     fn handle(&self, message: &mut Message, _sender: Sender<PeerMessage>) {
-        let upload_failed = UploadFailed::new_from_message(message);
-        info!("Upload failed for ${}", upload_failed.filename);
+        let filename = message.read_string();
+        info!("Upload failed for {}", filename);
     }
 }

soulseek-rs-lib/src/message/server/excluded_search_phrases.rs

@@ -31,16 +31,16 @@ impl MessageHandler<ServerMessage> for ExcludedSearchPhrasesHandler {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::message::framed;
 
     #[test]
     fn hostile_item_count_does_not_hang() {
         // item_count=u32::MAX with no phrases: the guard must make this return
         // promptly instead of looping ~4 billion times.
         let (tx, _rx) = std::sync::mpsc::channel();
-        let mut message = Message::new();
-        message.write_raw_bytes(vec![0u8; 8]);
-        message.write_int32(u32::MAX);
-        message.set_pointer(8);
+        let mut message = framed(|m| {
+            m.write_int32(u32::MAX);
+        });
         ExcludedSearchPhrasesHandler.handle(&mut message, tx);
     }
 }

soulseek-rs-lib/src/message/server/join_room.rs

@@ -33,17 +33,16 @@ impl MessageHandler<ServerMessage> for JoinRoomHandler {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::message::framed;
 
     #[test]
     fn hostile_user_count_does_not_hang() {
         // room="" then user_count=u32::MAX with no usernames: must return
         // promptly instead of looping ~4 billion times.
         let (tx, rx) = std::sync::mpsc::channel();
-        let mut message = Message::new();
-        message.write_raw_bytes(vec![0u8; 8]);
-        message.write_string("");
-        message.write_int32(u32::MAX);
-        message.set_pointer(8);
+        let mut message = framed(|m| {
+            m.write_string("").write_int32(u32::MAX);
+        });
 
         JoinRoomHandler.handle(&mut message, tx);
         match rx.try_recv() {
@@ -57,13 +56,12 @@ mod tests {
     #[test]
     fn forwards_room_and_member_list() {
         let (tx, rx) = std::sync::mpsc::channel();
-        let mut message = Message::new();
-        message.write_raw_bytes(vec![0u8; 8]);
-        message.write_string("nicotine");
-        message.write_int32(2);
-        message.write_string("alice");
-        message.write_string("bob");
-        message.set_pointer(8);
+        let mut message = framed(|m| {
+            m.write_string("nicotine")
+                .write_int32(2)
+                .write_string("alice")
+                .write_string("bob");
+        });
 
         JoinRoomHandler.handle(&mut message, tx);
         match rx.try_recv() {

soulseek-rs-lib/src/message/server/leave_room.rs

@@ -20,14 +20,14 @@ impl MessageHandler<ServerMessage> for LeaveRoomHandler {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::message::framed;
 
     #[test]
     fn forwards_left_room() {
         let (tx, rx) = std::sync::mpsc::channel();
-        let mut message = Message::new();
-        message.write_raw_bytes(vec![0u8; 8]);
-        message.write_string("jazz");
-        message.set_pointer(8);
+        let mut message = framed(|m| {
+            m.write_string("jazz");
+        });
 
         LeaveRoomHandler.handle(&mut message, tx);
         match rx.try_recv() {

soulseek-rs-lib/src/message/server/message_factory.rs

@@ -137,14 +137,6 @@ impl MessageFactory {
             .write_int32(port.into())
             .clone()
     }
-    #[must_use]
-    pub fn build_watch_user(token: u32) -> Message {
-        Message::new()
-            .write_raw_bytes([5, 0, 0, 0, 0].to_vec())
-            .write_int32(token)
-            .clone()
-    }
-
     /// Ask the server (code 7) for a user's online status.
     #[must_use]
     pub fn build_get_user_status(username: &str) -> Message {
@@ -280,15 +272,6 @@ fn test_build_get_user_stats() {
     assert_eq!(expect, message.get_data());
 }
 
-#[test]
-fn test_build_watch_user() {
-    let token: u32 = 223;
-    let message = MessageFactory::build_watch_user(token);
-    let expect: Vec<u8> = [5, 0, 0, 0, 0, 223, 0, 0, 0].to_vec();
-
-    assert_eq!(expect, message.get_data());
-}
-
 #[test]
 fn test_build_login_message() {
     let message = MessageFactory::build_login_message(

soulseek-rs-lib/src/message/server/message_user.rs

@@ -27,7 +27,6 @@ impl MessageHandler<ServerMessage> for MessageUser {
         );
 
         info!("[MessageUser] User message received:{:?}", user_message);
-        user_message.print();
 
         // Acknowledge freshly delivered messages so the server does not keep
         // re-sending them on every reconnect.

soulseek-rs-lib/src/message/server/privileged_users.rs

@@ -50,19 +50,12 @@ impl MessageHandler<ServerMessage> for CheckPrivilegesHandler {
 #[cfg(test)]
 mod tests {
     use super::*;
-
-    fn payload(build: impl FnOnce(&mut Message)) -> Message {
-        let mut message = Message::new();
-        message.write_raw_bytes(vec![0u8; 8]);
-        build(&mut message);
-        message.set_pointer(8);
-        message
-    }
+    use crate::message::framed;
 
     #[test]
     fn the_user_list_is_kept_not_just_counted() {
         let (tx, rx) = std::sync::mpsc::channel();
-        let mut message = payload(|m| {
+        let mut message = framed(|m| {
             m.write_int32(2)
                 .write_string("donor_a")
                 .write_string("donor_b");
@@ -80,7 +73,7 @@ mod tests {
     #[test]
     fn an_empty_list_is_still_an_answer() {
         let (tx, rx) = std::sync::mpsc::channel();
-        let mut message = payload(|m| {
+        let mut message = framed(|m| {
             m.write_int32(0);
         });
 
@@ -98,7 +91,7 @@ mod tests {
         // count=u32::MAX with no names: the guard must return promptly rather
         // than loop four billion times.
         let (tx, _rx) = std::sync::mpsc::channel();
-        let mut message = payload(|m| {
+        let mut message = framed(|m| {
             m.write_int32(u32::MAX);
         });
         PrivilegedUsersHandler.handle(&mut message, tx);
@@ -107,7 +100,7 @@ mod tests {
     #[test]
     fn our_own_remaining_privilege_time_is_reported() {
         let (tx, rx) = std::sync::mpsc::channel();
-        let mut message = payload(|m| {
+        let mut message = framed(|m| {
             m.write_int32(86_400);
         });
 

soulseek-rs-lib/src/message/server/room_list.rs

@@ -53,16 +53,7 @@ pub fn parse_room_list(message: &mut Message) -> Vec<RoomInfo> {
 #[cfg(test)]
 mod tests {
     use super::*;
-
-    /// Build a received message (8-byte header + payload) and position it the
-    /// way the dispatcher would.
-    fn framed(build: impl FnOnce(&mut Message)) -> Message {
-        let mut message = Message::new();
-        message.write_raw_bytes(vec![0u8; 8]);
-        build(&mut message);
-        message.set_pointer(8);
-        message
-    }
+    use crate::message::framed;
 
     #[test]
     fn parses_names_zipped_with_counts() {

soulseek-rs-lib/src/message/server/say_chatroom.rs

@@ -26,16 +26,16 @@ impl MessageHandler<ServerMessage> for SayChatroomHandler {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::message::framed;
 
     #[test]
     fn forwards_room_message() {
         let (tx, rx) = std::sync::mpsc::channel();
-        let mut message = Message::new();
-        message.write_raw_bytes(vec![0u8; 8]);
-        message.write_string("jazz");
-        message.write_string("alice");
-        message.write_string("hello everyone");
-        message.set_pointer(8);
+        let mut message = framed(|m| {
+            m.write_string("jazz")
+                .write_string("alice")
+                .write_string("hello everyone");
+        });
 
         SayChatroomHandler.handle(&mut message, tx);
         match rx.try_recv() {

soulseek-rs-lib/src/message/server/user_info.rs

@@ -56,21 +56,12 @@ impl MessageHandler<ServerMessage> for GetUserStatsHandler {
 #[cfg(test)]
 mod tests {
     use super::*;
-
-    /// Build a payload the dispatcher would hand a handler: 8 bytes of frame
-    /// header, then the fields, with the pointer parked at the payload.
-    fn payload(build: impl FnOnce(&mut Message)) -> Message {
-        let mut message = Message::new();
-        message.write_raw_bytes(vec![0u8; 8]);
-        build(&mut message);
-        message.set_pointer(8);
-        message
-    }
+    use crate::message::framed;
 
     #[test]
     fn user_status_is_parsed_with_its_privileged_flag() {
         let (tx, rx) = std::sync::mpsc::channel();
-        let mut message = payload(|m| {
+        let mut message = framed(|m| {
             m.write_string("alice").write_int32(2).write_int8(1);
         });
 
@@ -93,7 +84,7 @@ mod tests {
     fn user_stats_skip_the_two_obsolete_fields() {
         let (tx, rx) = std::sync::mpsc::channel();
         // username, speed, obsolete, obsolete, files, folders
-        let mut message = payload(|m| {
+        let mut message = framed(|m| {
             m.write_string("bob")
                 .write_int32(1024)
                 .write_int32(0)

soulseek-rs-lib/src/message/server/user_joined_room.rs

@@ -23,15 +23,14 @@ impl MessageHandler<ServerMessage> for UserJoinedRoomHandler {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::message::framed;
 
     #[test]
     fn forwards_user_joined() {
         let (tx, rx) = std::sync::mpsc::channel();
-        let mut message = Message::new();
-        message.write_raw_bytes(vec![0u8; 8]);
-        message.write_string("jazz");
-        message.write_string("carol");
-        message.set_pointer(8);
+        let mut message = framed(|m| {
+            m.write_string("jazz").write_string("carol");
+        });
 
         UserJoinedRoomHandler.handle(&mut message, tx);
         match rx.try_recv() {

soulseek-rs-lib/src/message/server/user_left_room.rs

@@ -21,15 +21,14 @@ impl MessageHandler<ServerMessage> for UserLeftRoomHandler {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::message::framed;
 
     #[test]
     fn forwards_user_left() {
         let (tx, rx) = std::sync::mpsc::channel();
-        let mut message = Message::new();
-        message.write_raw_bytes(vec![0u8; 8]);
-        message.write_string("jazz");
-        message.write_string("carol");
-        message.set_pointer(8);
+        let mut message = framed(|m| {
+            m.write_string("jazz").write_string("carol");
+        });
 
         UserLeftRoomHandler.handle(&mut message, tx);
         match rx.try_recv() {

soulseek-rs-lib/src/message/server/wish_list_interval.rs

@@ -26,14 +26,14 @@ impl MessageHandler<ServerMessage> for WishListIntervalHandler {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::message::framed;
 
     #[test]
     fn the_announced_interval_is_reported_not_discarded() {
         let (tx, rx) = std::sync::mpsc::channel();
-        let mut message = Message::new();
-        message.write_raw_bytes(vec![0u8; 8]);
-        message.write_int32(720);
-        message.set_pointer(8);
+        let mut message = framed(|m| {
+            m.write_int32(720);
+        });
 
         WishListIntervalHandler.handle(&mut message, tx);
         match rx.try_recv() {