Scaffold backend (FastAPI/uv) and frontend (SvelteKit/bun)

Backend: FastAPI app with health check, AppError hierarchy, stderr
logging via LOG_LEVEL, ruff+pyright(strict) config, pytest passing.

Frontend: SvelteKit (TS) with prettier, eslint, vitest (unit +
component), adapter-node for self-hosted deployment on Zeus.

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

README.md

@@ -8,13 +8,26 @@ See [SPEC.md](SPEC.md) for the full spec, architecture, and design areas.
 
 ## Status
 
-Spec-only. Implementation not started yet.
+Scaffolded, no features implemented yet. `backend/` and `frontend/` both run
+and have a passing test suite; actual simulation/narration/TTS logic is next.
 
-## Stack (planned)
+## Stack
 
-- Frontend: SvelteKit
-- Backend: FastAPI (Python, `uv`)
+- Frontend: SvelteKit (`frontend/`) — `bun`
+- Backend: FastAPI (`backend/`) — `uv`
 - TTS: Piper (server-side)
 - Narration: Anthropic Haiku API (server-side)
 - Reverse proxy: Caddy
 - Deployment target: Zeus, `sagaphone.orbitstack.casa`
+
+## Dev
+
+```bash
+# backend
+cd backend && uv sync && uv run uvicorn app.main:app --reload
+
+# frontend
+cd frontend && bun install && bun run dev
+```
+
+Each subproject's own README has more detail (lint/test/typecheck commands).