tmux: use send-keys -l for literal text input

Without -l, tmux send-keys treats spaces as key-name separators,
so multi-word messages like "This is your time" get split into
individual unrecognized key names instead of being typed as text.
This caused idle nudges to arrive as blank messages.

src/bin/poc-daemon/tmux.rs

@@ -51,8 +51,12 @@ pub fn send_prompt(pane: &str, msg: &str) -> bool {
     }
     thread::sleep(Duration::from_secs(1));
 
-    // Type the message
+    // Type the message (literal mode so spaces aren't key separators)
-    if !send(&[msg]) {
+    let ok = Command::new("tmux")
+        .args(["send-keys", "-t", pane, "-l", msg])
+        .output()
+        .is_ok();
+    if !ok {
         return false;
     }
     thread::sleep(Duration::from_millis(500));