Release 0.9.18 "Chuck" - Sucess begins inside

This release includes a number of under-the-hood improvements that
will make the life of maintainers easier in the long run.

New features
============

* Implement the `Chuck` command
* Make `xq` recognize more patterns during simplification
* List the menus in the help file
* Support for tables in the help file
* Extend `re`, `im`, `conj` and `sign` to lists and arrays
* Add `norm` as a separate command from `abs`
* `ListRecursionDepth` setting for `map`, `reduce`, `filter`

Bug fixes
=========

* Remove `-fsanitize` option on macOS (hangs on macOS 26.4)
* Fix incorrect evaluation of constants during simplification

Improvements
============

* Switch to the make-it-quick build system
* Shared cross-platorm clipboard code
* Automate the build of releases
* Put the variables naming expression patterns in a namespace
* Improved instructions for AI agents
* `abs` on vectors and matrices now computes absolute value
* Repair GitHub actions
* Improve solver shuffle around singularities and errors
* Fix path for grep testing in case of example test failure

Signed-off-by: Christophe de Dinechin <christophe@dinechin.org>