fix(cli): the advertised wait idiom fails in one of its own end states

`tty7 wait`'s headline example is

    tty7 wait %3 && tty7 capture %3 --plain

and `exit` is one of the three states `--until` waits for by default. Run
it that way and the pane is gone by the time capture runs: wait reports
`exit` and succeeds, `&&` proceeds, and capture answers that nothing is
running. An agent following the documented pattern gets no output for a
command that produced some.

The example is right for an agent — `waiting` and `done` leave the pane
alive. It is wrong for a plain command, which finishes by the shell
exiting. Spell both out in `wait`'s long help, and say plainly that
`exit` is the end state with nothing left to read.

Verified against a live server: `wait --until free` blocks for the
command (5s for a 4s sleep), and the capture after it finds the marker.

Also: a server running one pane had `doctor` say "1 panes" on its first
line. It is the first thing a new user runs. Every other count in the
tree is already plural-aware — the GUI routes these through `t_plural`
with "one"/"other" branches, and the CLI's other count (`closed N panes`)
handles the single case separately — so this was the last one.

crates/tty7-cli/src/cli.rs

@@ -95,7 +95,18 @@ pub enum Command {
 
     #[command(
         about = "Block until a pane's agent needs input, finishes its turn, or the pane \
-                 exits — the orchestration primitive: `tty7 wait %3 && tty7 capture %3 --plain`"
+                 exits — the orchestration primitive: `tty7 wait %3 && tty7 capture %3 \
+                 --plain`",
+        long_about = "Block until a pane's agent needs input, finishes its turn, or the \
+                      pane exits — the orchestration primitive:\n\n    \
+                      tty7 wait %3 && tty7 capture %3 --plain\n\n\
+                      That pairs with an agent, whose pane is still alive in `waiting` and \
+                      `done`. For a plain command, wait for `free` instead:\n\n    \
+                      tty7 wait %3 --until free && tty7 capture %3 --plain\n\n\
+                      `exit` is the one end state with nothing left to read: the pane's \
+                      output goes with the pane, and the workspace keeps only a leaf the \
+                      GUI can revive into a fresh shell. Capture before the shell exits, \
+                      or run the command under `tty7 run`, which streams it."
     )]
     Wait(WaitArgs),
 

crates/tty7-cli/src/commands.rs

@@ -1517,8 +1517,11 @@ fn doctor(ctx: &Context, backend: &mut dyn Backend) -> Result<Outcome> {
             rows.push(vec![
                 "status".to_string(),
                 format!(
-                    "pid {}, up {}s, {} panes",
+                    "pid {}, up {}s, {} pane{}",
-                    status.pid, status.uptime_secs, status.panes
+                    status.pid,
+                    status.uptime_secs,
+                    status.panes,
+                    if status.panes == 1 { "" } else { "s" }
                 ),
             ]);
             let routes = match backend.control(ControlRequest::Routes)? {
@@ -3853,6 +3856,45 @@ mod tests {
         assert!(out.contains("set (/cfg/tty7)"), "{out}");
     }
 
+    /// A server running one pane said "1 panes".
+    ///
+    /// The count comes straight off the status reply, so every fresh server
+    /// says it — `doctor` is the first thing a new user runs, and the first
+    /// line it shows them was ungrammatical.
+    #[test]
+    fn doctor_counts_one_pane_in_the_singular() {
+        use tty7_core::daemon::control::ServerStatus;
+
+        let status = |panes: u64| ServerStatus {
+            pid: 4242,
+            uptime_secs: 61,
+            panes,
+            control_version: CONTROL_VERSION,
+            protocol_version: PROTOCOL_VERSION,
+            build: "26.7.5".into(),
+            socket: "127.0.0.1:5555".into(),
+        };
+        let line = |panes: u64| {
+            let mut backend = mock();
+            backend.replies.push_back(ReplyOk::Status(status(panes)));
+            backend.replies.push_back(ReplyOk::Routes(Vec::new()));
+            human(run_cli(
+                &["tty7", "doctor"],
+                &Context::default(),
+                &mut backend,
+            ))
+        };
+
+        assert!(
+            line(1).contains("1 pane\n") || line(1).contains("1 pane "),
+            "{}",
+            line(1)
+        );
+        assert!(!line(1).contains("1 panes"), "{}", line(1));
+        assert!(line(0).contains("0 panes"), "{}", line(0));
+        assert!(line(2).contains("2 panes"), "{}", line(2));
+    }
+
     /// Missing hooks are the reason a perfectly healthy-looking agent never
     /// reports and `tty7 wait` sits there until it times out. `doctor` is the
     /// verb people run when something is not working, so it is where that has