Adds the full development-toolchain image variant. - Publishes `psyb0t/aicodebox:latest-full` alongside the minimal `latest` image. The matching version tag is `v0.15.0-full`. - Moves the shared Go, Node, Python, editor, diagnostic, database-client, and operations toolchain into the base image, so agent images can inherit it instead of each rebuilding it. - Adds `make build-full`, `make build-all`, and `make test-full-image`. CI publishes the matching minimal image before building the full variant.