feat: publish versioned agent images — compose should use image: not build: (#429)

- Generated compose now uses `image: ghcr.io/disinto/{agents,edge}` instead
  of `build:` directives; `disinto init --build` restores local-build mode
- Add VOLUME declarations to agents, reproduce, and edge Dockerfiles
- Add CI pipeline (.woodpecker/publish-images.yml) to build and push images
  to ghcr.io/disinto on tag events
- Mount projects/, .env, and state/ into agents container for runtime config
- Skip pre-build binary download when compose uses registry images

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker/reproduce/Dockerfile

@@ -7,5 +7,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 RUN useradd -m -u 1000 -s /bin/bash agent
 COPY docker/reproduce/entrypoint-reproduce.sh /entrypoint-reproduce.sh
 RUN chmod +x /entrypoint-reproduce.sh
+VOLUME /home/agent/data
+VOLUME /home/agent/repos
+
 WORKDIR /home/agent
 ENTRYPOINT ["/entrypoint-reproduce.sh"]