v0.1.4 — prebuilt Docker image on GHCR (closes #5)

Adds a GitHub Actions workflow that builds and pushes the Docker image
to ghcr.io/rgjorge/containerflow on every tag push, so end users can run
ContainerFlow without cloning the repo or building locally.

- New workflow: .github/workflows/docker-release.yml
- docker-compose.yml: uses the prebuilt image from GHCR by default
- New docker-compose.local.yml: override for building from source (devs)
- .env.example: simplified + adds COMPOSE_FILE toggle for local build
- README EN + ES: quick-start updated to no-clone flow
- .gitignore: ignore task/ planning notes dir

.gitignore

@@ -18,3 +18,6 @@ recomendaciones.md
 docs/reddit.md
 # AI assistant context — internal, not for public repo
 CLAUDE.md
+
+# Planning notes — internal, not for public repo
+task/