Add dedicated hotkey (e.g. Shift+Q) for cd_on_quit behavior

[yorukot]

The part you want to Enhancement Introduce a new hotkey (such as Shift+Q) to trigger cd_on_quit, allowing users to explicitly choose between a normal quit and quitting with directory change.

Why it is necessary to enhancement Currently, users can only choose one quit behavior via configuration (cd_on_quit = true/false). However, in real-world usage, sometimes users simply want to exit, and other times they want to cd into the last navigated directory. The current design forces a single behavior, which limits flexibility. By supporting both through separate keybindings, we can better accommodate both workflows without requiring config changes.

Additional context This idea was brought up during the discussion in #919, where users expressed a desire to preserve both quit and cd_on_quit functionality. A dedicated hotkey like Shift+Q could be a clean and intuitive solution.