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>

.gitea/workflows/dev-deploy.yaml

@@ -100,9 +100,10 @@ jobs:
 
       - name: Bring up the stack
         working-directory: tools/dev-deploy
-        env:
-          GALAXY_DEV_GAME_STATE_DIR: ${{ env.HOME }}/.galaxy-dev/game-state
         run: |
+          # Resolve in the shell, not in YAML expressions — `env.HOME`
+          # is empty at the workflow-evaluation stage.
+          export GALAXY_DEV_GAME_STATE_DIR="$HOME/.galaxy-dev/game-state"
           mkdir -p "$GALAXY_DEV_GAME_STATE_DIR"
           docker compose up -d --wait --remove-orphans