Fix rego-tunnel docker-compose.json format and add build folder

- Convert environment from array to object format (runtipi requirement)
- Remove hardcoded KEY from docker-compose.json
- Add build folder with custom Dockerfile and rego scripts

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/rego-tunnel/build/.dockerignore

@@ -0,0 +1,14 @@
+.dockerignore
+.devcontainer
+.git
+.github
+.gitignore
+.gitlab-ci.yml
+.gitmodules
+Dockerfile
+Dockerfile.archive
+compose.yml
+compose.yaml
+docker-compose.yml
+docker-compose.yaml
+*.md