chore(ci): tag-triggered release workflow and helpers

Add .gitea/workflows/release.yml: on v* tag push (or manual
dispatch) build the Docker image and push
git.linuxhg.com/games-database/games-frontend:<tag> plus
:latest, then create/update the Gitea Release from the
annotated tag message. No build-args needed since the build
is env-free. Main-branch pushes do nothing.

Add cliff.toml (conventional-commit release notes), Makefile
release target, and ./release wrapper (accepts 1.0 or v1.0).
Same flow as the other repos; needs a REGISTRY_TOKEN repo
Actions secret (PAT with write:package and write:repository).

release

@@ -0,0 +1,15 @@
+#!/usr/bin/env sh
+# Project-attached wrapper around `make release` so you can run:
+#   ./release v0.1.0   (or)   ./release 0.1.0
+# instead of:
+#   make release VERSION=v0.1.0
+# Lives in the repo (no machine-specific alias needed).
+set -eu
+
+[ "$#" -ge 1 ] || { echo "Usage: ./release v0.1.0" >&2; exit 1; }
+
+# Accept "0.1.0" or "v0.1.0"; ensure the tag starts with 'v' (the workflow
+# only triggers on v* tags).
+VERSION="v${1#v}"
+
+exec make release "VERSION=${VERSION}"