DIAG(ptyd): log pty.input line-discipline (icanon/vmin -> cooked/mosi) + slave read mosi state

ptyd/src/pty.rs

@@ -246,6 +246,19 @@ impl Pty {
         }
 
         self.update();
+        if !buf.is_empty() {
+            let cc = self.termios.c_cc;
+            eprintln!(
+                "ptyd-diag: input {} bytes icanon={} echo={} vmin={} vtime={} -> cooked={} mosi={}",
+                buf.len(),
+                icanon,
+                echo,
+                cc[VMIN],
+                cc[VTIME],
+                self.cooked.len(),
+                self.mosi.len(),
+            );
+        }
     }
 
     pub fn output(&mut self, buf: &[u8]) {

ptyd/src/subterm.rs

@@ -51,6 +51,14 @@ impl Resource for PtySubTerm {
 
             pty.update();
 
+            if !pty.mosi.is_empty() {
+                eprintln!(
+                    "ptyd-diag: subterm read: mosi has {} packet(s), first len {}",
+                    pty.mosi.len(),
+                    pty.mosi.front().map(|p| p.len()).unwrap_or(0),
+                );
+            }
+
             if let Some(packet) = pty.mosi.pop_front() {
                 let mut i = 0;