Move Dockerfile, entrypoint.sh, docker-compose.yml to repo root

Komodo's build ran `docker build -f Dockerfile .` from inside docker/,
which set the build context to docker/ — a directory that contains neither
package.json nor a nested docker/entrypoint.sh, so both COPY steps failed.
Moving these three files to the repo root makes `docker build .` from the
repo root work with default Komodo settings (no per-build-tool config).

- Dockerfile: update COPY entrypoint.sh path (drops docker/ prefix)
- docker-compose.yml: build.context = . (drops dockerfile: override)
- README.md: docker compose build (drops -f docker/docker-compose.yml)

Dockerfile

@@ -0,0 +1,34 @@
+# syntax=docker/dockerfile:1.7
+FROM node:22-alpine AS build
+
+# native builds for better-sqlite3
+RUN apk add --no-cache python3 make g++ sqlite
+
+WORKDIR /app
+COPY package.json package-lock.json* ./
+RUN --mount=type=cache,target=/root/.npm \
+    npm install --include=dev
+
+COPY . .
+RUN npm run build \
+ && npm prune --omit=dev
+
+# ---- runtime ----
+FROM node:22-alpine
+
+RUN apk add --no-cache sqlite tini rsync
+
+WORKDIR /app
+COPY --from=build /app/build       ./build
+COPY --from=build /app/node_modules ./node_modules
+COPY --from=build /app/package.json ./package.json
+COPY --from=build /app/src/lib/server/db/schema.sql ./build/schema.sql
+COPY entrypoint.sh /entrypoint.sh
+RUN chmod +x /entrypoint.sh
+
+ENV NODE_ENV=production
+ENV PORT=3000
+ENV HOST=0.0.0.0
+EXPOSE 3000
+
+ENTRYPOINT ["/sbin/tini", "--", "/entrypoint.sh"]