fix: restart incompatible daemons

README.md

@@ -197,6 +197,10 @@ prints a session's effective timeouts.
 Each session has its own daemon, so `daemon stop` needs `--session <name>` or
 `--all`. `close` stops it too.
 
+When a client finds a daemon from another `tui-test` version, it shuts that
+daemon down and starts the current version before sending the command. The
+restart is serialized per session so concurrent clients cannot race.
+
 `open` waits for a prompt before returning, `run` does not. Override with
 `--wait-ready` / `--no-wait-ready`. An explicit `--wait-ready` fails (exit 1) if
 no prompt appears; `open`'s implicit wait reports `ready` in its payload either

SKILL.md

@@ -35,6 +35,9 @@ Three commands let an agent look up the rest of the surface instead of guessing:
   (`assertion` / `usage` / `no_session` / `internal`).
 - **Verbose.** `--verbose` / `-v` starts the daemon with a full PTY traffic log
   (see [Debugging](#debugging)). Only takes effect when the daemon starts.
+- **Daemon upgrades.** A client automatically replaces a daemon from another
+  `tui-test` version. Per-session locking prevents concurrent clients from
+  racing the restart.
 - **Defaults.** New sessions are `80x30`. Timeouts come in five classes: `text`
   and `idle` default to 5s; `command`, `exit`, and `ready` to 30s. Set a session
   default with `open --timeout-<class> <ms>`, or override one call with

crates/tui-test-cli/src/config.rs

@@ -21,6 +21,10 @@ pub fn pid_file(session: &str) -> PathBuf {
     home_dir().join(format!("{session}.pid"))
 }
 
+pub fn daemon_lock_file(session: &str) -> PathBuf {
+    home_dir().join(format!("{session}.pid.lock"))
+}
+
 pub fn log_file(session: &str) -> PathBuf {
     home_dir().join(format!("{session}.log"))
 }