Scaffold orchestrator-ui (React + Vite + TS; eslint/prettier, vitest, tsc)

[Ryan-Atkinson87]

Scaffold the orchestrator-ui React/Vite project and establish its test/lint/typecheck toolchain — filling the frontend command placeholders left open since Foundations.

Spec: §12 UI scope, §13 tech stack (React + Vite), §2 architecture.

Acceptance criteria

• orchestrator-ui/ scaffolded as a React + Vite + TypeScript project (§13).
• Test, lint, and typecheck commands established and runnable (e.g. Vitest, ESLint/Prettier, tsc --noEmit); a trivial passing test exists so the gates are real.
• CLAUDE.md <FRONTEND_TEST_CMD> / <FRONTEND_LINT_CMD> / <FRONTEND_TYPECHECK_CMD> placeholders replaced with the actual commands; these gates become mandatory from this point (per workflow-testing note).
• Builds and serves behind the existing Compose service / Dockerfile from Foundations (Docker Compose stack skeleton (Traefik + 7 services + Dockerfiles) #7); no hardcoded API URLs — the API base is configured by environment.
• README updated with frontend dev/build/test commands.
• No devDependencies imported at runtime.

label: chore

Depends on: #7, #2