refactor(ipc): read requests with cce_ui::ipc::read_request_line

Byte-identical to the copy deleted here; it lives in cce-ui now (40c66d4).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

 src/ipc.rs | 36 +-----------------------------------
 1 file changed, 1 insertion(+), 35 deletions(-)

diff --git a/src/ipc.rs b/src/ipc.rs
index cf65943..514c0a4 100644
--- a/src/ipc.rs
+++ b/src/ipc.rs
@@ -114,7 +114,7 @@ pub fn spawn_listener(sender: calloop::channel::Sender<AppMessage>) {
     std::thread::spawn(move || {
         for conn in listener.incoming() {
             let Ok(conn) = conn else { continue };
-            let Some(line) = read_request_line(&conn, 64 * 1024, IO_TIMEOUT) else {
+            let Some(line) = cce_ui::ipc::read_request_line(&conn, 64 * 1024, IO_TIMEOUT) else {
                 continue;
             };
             let _ = conn.set_read_timeout(Some(IO_TIMEOUT));
@@ -622,37 +622,3 @@ mod tests {
         }
     }
 }
-
-/// One request line from a control-socket client, bounded in size and in
-/// TOTAL time. Until 2026-10-02 this was `BufReader::read_line` on a socket
-/// with a per-read timeout only, so a client that connected and said nothing (or trickled a
-/// byte at a time) held the listener thread as long as it kept trickling. None on EOF before any byte, timeout,
-/// overflow or a read error.
-fn read_request_line(conn: &std::os::unix::net::UnixStream, limit: usize, deadline: std::time::Duration) -> Option<String> {
-    use std::io::Read;
-    let until = std::time::Instant::now() + deadline;
-    let mut buf: Vec<u8> = Vec::new();
-    let mut chunk = [0u8; 4096];
-    let mut reader = conn;
-    loop {
-        let left = until.checked_duration_since(std::time::Instant::now()).filter(|d| !d.is_zero())?;
-        conn.set_read_timeout(Some(left)).ok()?;
-        let n = reader.read(&mut chunk).ok()?;
-        if n == 0 {
-            if buf.is_empty() {
-                return None;
-            }
-            break;
-        }
-        buf.extend_from_slice(&chunk[..n]);
-        if let Some(end) = buf.iter().position(|&b| b == b'\n') {
-            buf.truncate(end + 1);
-            break;
-        }
-        if buf.len() > limit {
-            return None;
-        }
-    }
-    let _ = conn.set_read_timeout(None);
-    String::from_utf8(buf).ok()
-}