This PR updates JoinMarket to the latest tested commit with Python 3.12/3.13 support and addresses dialog display issues.
### Changes
#### JoinMarket Update
- Update to commit `ce32baf` (latest tested commit from master)
- Refactored install.joinmarket.sh to support both tag-based and commit-based installations
- Improved signature verification using verify.git.sh
- Updated menu.update.sh to display commit hash when using commit-based version
#### Python Support
- Added support for Python 3.12 and 3.13
- Changed version detection order to prefer newer Python versions (3.13 → 3.12 → 3.11 → 3.10 → 3.9 → 3.8)
#### Dialog Fixes
- **Fix border visibility**: Changed dialog border color from `(BLACK,BLACK,ON)` to `(CYAN,BLACK,ON)` in .dialogrc for better visibility
- **Terminal compatibility**: Added fallback for unknown terminal types (e.g., `xterm-ghostty`) by setting `TERM=xterm-256color` when `infocmp` fails
- **Fix box drawing characters**: Set `NCURSES_NO_UTF8_ACS=1` to fix dialog box rendering issues
#### Documentation
- Fixed typo in prepare_remote_node.md: "numbes" → "numbers"
* refactor install to add new user
* add option to test a joininbox pr
* reorder vars and update FAQ
* record the qtgui entry and prepare ${user}
* check entry after the user is created
as suggested in: https://github.com/openoms/joininbox/issues/28
the main menu "Exit" button now drops to the command line
the separate "Exit to the Command Line" option is removed
Submenus use the label "Back" inplace of "Cancel"
