feat: surface the version and adopt semantic versioning

The version was declared in the project() call and used nowhere. It is now
generated into version.h from that single declaration, so nothing repeats
the literal, and it reaches the places it is actually wanted: --version,
--help, the window title, and QApplication.

--version and --help are answered before the web engine schemes are
registered and before QApplication is constructed. Printing one line does
not need a GUI, and both must work on a machine where the GUI cannot open.

Staying at 0.1.0 rather than calling this 1.0.0: under semver, 0.x is where
the interface may still change, and for this project the interface is the
config file format and the bindable action names. Both are one manual
verification pass old. 1.0.0 becomes a deliberate decision to stop changing
them under users.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

0 files changed, 0 insertions, 0 deletions