Give development builds their own Debian package version

make deb versions a build that isn't a release after the last tag:
0.2.0~rc.1+git3.gca0f148, plus the build time (.m<UTC time>) with
uncommitted changes. apt sorts it after that RC and before the next, so
installing it over the RC or an older build is an upgrade and needs no
--reinstall. mkdeb.sh removes older packages of the same architecture
from dist/ so the install globs match one package.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -95,6 +95,11 @@ All notable changes to Jarl are documented here. The format follows
   development builds and how far past the last tag they are: `dev
   ca0f148b78b6 (3 commits after v0.2.0-rc.1)`. In 0.2.0-rc.1 they still
   printed `0.2.0-rc.1 (ca0f148b78b6)`.
+- `make deb` gives development builds their own package version after
+  the last tag (`0.2.0~rc.1+git3.gca0f148`, plus the build time with
+  uncommitted changes). Installing one over the RC or an older build is
+  an upgrade: no more `apt install --reinstall`. It also removes older
+  packages from `dist/` (docs/development.md).
 - The view in the zone list, and on the zone page, links to that view,
   and the views page highlights it. It used to be plain text, and the zone
   page linked to the views page as a whole.