Bring repo up to REPO_POLICIES.md standards

- Add prettier (4-space indents) and reformat all files
- Add Makefile with test/lint/fmt/fmt-check/check/docker targets
- Add MIT LICENSE file
- Add REPO_POLICIES.md
- Fix Dockerfile: listen on 8080 with PORT env var via envsubst
- Restructure README.md with all required sections
- Set up pre-commit hook (make check)
- Update .prettierignore, .gitignore, .dockerignore

.prettierignore

@@ -0,0 +1,4 @@
+dist/
+node_modules/
+yarn.lock
+.claude/