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).

packages/server/Dockerfile

@@ -0,0 +1,54 @@
+# syntax=docker/dockerfile:1.7
+# Authoritative Bun WebSocket server for @paratype/chess.
+# Build context: monorepo root (so workspace deps resolve).
+
+FROM oven/bun:1.3 AS deps
+WORKDIR /app
+
+# Manifests first for cacheable installs.
+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
+
+# ---- builder: compile @paratype/rete (server resolves its "import"
+# field to dist/index.js, so we MUST build it before runtime).
+FROM deps AS builder
+COPY packages/rete packages/rete
+RUN bun run --filter @paratype/rete build
+
+# Bring in remaining sources needed at runtime.
+COPY packages/chess/src packages/chess/src
+COPY packages/chess/package.json packages/chess/
+COPY packages/server packages/server
+
+# ---- runtime
+FROM oven/bun:1.3-slim AS runtime
+WORKDIR /app
+ENV NODE_ENV=production \
+    PORT=7357 \
+    LOG_LEVEL=info
+
+COPY --from=builder /app/node_modules ./node_modules
+COPY --from=builder /app/package.json ./package.json
+
+# rete: built dist + its symlinked node_modules
+COPY --from=builder /app/packages/rete/dist packages/rete/dist
+COPY --from=builder /app/packages/rete/package.json packages/rete/package.json
+COPY --from=builder /app/packages/rete/node_modules packages/rete/node_modules
+
+# chess: source consumed by server.ts via "default" export, plus its
+# per-package node_modules so symlinked deps (zod, etc.) resolve.
+COPY --from=builder /app/packages/chess/src packages/chess/src
+COPY --from=builder /app/packages/chess/package.json packages/chess/package.json
+COPY --from=builder /app/packages/chess/node_modules packages/chess/node_modules
+
+# server: full copy already includes its node_modules.
+COPY --from=builder /app/packages/server packages/server
+
+EXPOSE 7357
+USER bun
+CMD ["bun", "run", "packages/server/src/index.ts"]