Introduces a static-binary build and Debian package (amd64/arm64) with
version/commit/date stamped via -ldflags. Ships section-1 manpages for
ctool, ctfetch, and ctail. Adds a `version` subcommand reachable as
`ctool version`, `ctool -version`, `ctool --version`, `ctool fetch
version`, `ctool tail version`, and via the ctfetch/ctail symlinks. Adds
tests covering the dispatcher, fetch/tail argument parsing, and the
formatter/helper functions. Adds a retrofit design document modelled on
the vpp-maglev one, with FRs and NFRs for each tool and the dispatcher.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
