feat: show focused pane title in tmux status-right

Lead status-right with the focused pane's terminal title (truncated to 21
cols) and widen status-right-length to 64, restoring the preview tmux shows by
default.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/hqt/tmux/runner.py

@@ -57,9 +57,12 @@ _SESSION_THEME_OPTIONS: list[tuple[str, str]] = [
         f"#[fg={_FRAPPE['crust']},bg={_FRAPPE['blue']},bold] #S "
         f"#[fg={_FRAPPE['blue']},bg={_FRAPPE['mantle']},nobold] ",
     ),
-    ("status-right-length", "40"),
+    ("status-right-length", "64"),
     (
         "status-right",
+        # Lead with the focused pane's terminal title (whatever the harness sets,
+        # truncated to 21 cols) — this restores the preview tmux shows by default.
+        f"#[fg={_FRAPPE['text']},bg={_FRAPPE['mantle']}] #{{=21:pane_title}} "
         f"#[fg={_FRAPPE['overlay1']},bg={_FRAPPE['mantle']}] %H:%M "
         f"#[fg={_FRAPPE['crust']},bg={_FRAPPE['blue']},bold] %d %b ",
     ),