fix: disable flow control (-ixon) for Ctrl+Q, constrain prompt/hint to chat-w

- Added -ixon to stty so Ctrl+Q (XON byte) isn't swallowed by the
  terminal driver and reaches the TUI as :CTRL-Q
- view-input now truncates the prompt (> prefix + visible text) to
  chat-w - 2 characters, and the hint to chat-w characters, so
  neither extends into the sidebar area

org/channel-tui-view.org

@@ -222,12 +222,14 @@ Returns a list of strings, one per line."
          (h (or (and (numberp h) (> h 0) h) 24))
          (sidebar-w (if (and (st :sidebar-visible) (>= w 60)) (or (st :sidebar-width) 30) 0))
          (chat-w (- w sidebar-w))
+         (prompt-w (- chat-w 2))  ; leave room for "> "
          (text (input-string))
          (pos (or (st :cursor-pos) 0))
-         (display-start (max 0 (- pos (1- chat-w))))
-         (visible (subseq text display-start (min (length text) (+ display-start chat-w)))))
-    (cl-tty.backend:draw-text fb 0 (- h 2) (format nil " Ctrl+P palette | Up/Dn history | Tab complete")
-                              (theme-color :hint) nil)
+         (display-start (max 0 (- pos (1- prompt-w))))
+         (visible (subseq text display-start (min (length text) (+ display-start prompt-w))))
+         (hint " Ctrl+P palette | Up/Dn history | Tab complete")
+         (hint (if (> (length hint) chat-w) (subseq hint 0 chat-w) hint)))
+    (cl-tty.backend:draw-text fb 0 (- h 2) hint (theme-color :hint) nil)
     (cl-tty.backend:draw-text fb 0 (- h 3) (format nil "> ~a" visible) (theme-color :input-fg) nil)))
 #+end_src