dev-deploy: fix backend startup in CI

Two bugs surfaced on the first real merge into development:

1. `${{ env.HOME }}` evaluates to empty string at the workflow stage,
   so GALAXY_DEV_GAME_STATE_DIR became `/.galaxy-dev/game-state`.
   Resolve in the shell instead of YAML.

2. The compose bind-mount of GeoIP2-Country-Test.mmdb referenced a
   path inside the runner's workspace volume, which the host Docker
   daemon cannot see — it created an empty directory and the backend
   crashed with "geoip database: is a directory" in a restart loop.
   Bake the file into the backend image so dev-deploy no longer needs
   a bind-mount; local-dev compose still mounts it on top for swap-in
   during development.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tools/local-dev/backend.Dockerfile

@@ -24,6 +24,16 @@ COPY pkg/transcoder/ ./pkg/transcoder/
 COPY pkg/util/       ./pkg/util/
 COPY backend/        ./backend/
 
+# Bake the GeoIP test database into the build context so downstream
+# stages can copy it into the runtime image. The path is the
+# `MaxMind-DB` git submodule under `pkg/geoip/test-data/`; the file is
+# the smallest country DB MaxMind publishes and is what every other
+# dev-stack uses. Baking it lets dev-deploy skip the bind-mount that
+# fails on runner-workspace volumes the host Docker daemon cannot see.
+RUN mkdir -p /out/var/lib/galaxy
+COPY pkg/geoip/test-data/test-data/GeoIP2-Country-Test.mmdb \
+     /out/var/lib/galaxy/geoip.mmdb
+
 RUN <<'EOF' cat > go.work
 go 1.26.2
 
@@ -67,5 +77,6 @@ EXPOSE 8080
 EXPOSE 8081
 
 COPY --from=builder /out/backend /usr/local/bin/backend
+COPY --from=builder /out/var/lib/galaxy/geoip.mmdb /var/lib/galaxy/geoip.mmdb
 
 ENTRYPOINT ["/usr/local/bin/backend"]