infra: docker compose dev + production Dockerfiles

- docker-compose.dev.yml: hot-reload dev stack (rete-watch + server :7357 + web :5173)
- docker-compose.yml: production stack
- packages/chess/Dockerfile + nginx.conf: chess web image
- packages/server/Dockerfile: server image
- Dockerfile.dev: shared dev base image (Bun + workspace deps preinstalled)
- .dockerignore: build context exclusions

Used by Playwright e2e tests (run via .sisyphus/scripts/run-pw.sh which connects to the running dev stack instead of spawning its own server).

Dockerfile.dev

@@ -0,0 +1,16 @@
+# syntax=docker/dockerfile:1.7
+# Dev image — Bun + workspace deps preinstalled.
+# Source is NOT baked in; docker-compose.dev.yml bind-mounts the repo
+# at /app so file edits propagate live into the container.
+
+FROM oven/bun:1.3
+WORKDIR /app
+
+# Manifests only — keeps the install layer cacheable across source edits.
+COPY package.json bun.lock ./
+COPY tsconfig.base.json tsconfig.json ./
+COPY packages/rete/package.json packages/rete/
+COPY packages/chess/package.json packages/chess/
+COPY packages/server/package.json packages/server/
+
+RUN bun install --frozen-lockfile