Install the binary as /usr/bin/mistralrs-server-<flavour> using the
standard %{_bindir} macro. The update-alternatives system manages
the /usr/bin/mistralrs-server symlink as before. Removes the
non-standard /opt/mistralrs/<flavour>/bin/ directory structure.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>