Merge offline-package workflow jobs into runtime-release.yaml:
build (one linux+darwin matrix) -> publish (outputs runtime_tag) ->
build-offline-package (matrix) -> test-offline-package (matrix) ->
publish-release. One-directional deps: publish-release needs
test-offline-package needs build-offline-package. Offline build uses the
in-pipeline runtime_tag, and publish-release folds in the console-runtime
download (from aaf6c47) plus the >2GiB split-upload. The standalone
offline-package-ai-workspace-installer.yaml is now redundant (dispatch-only;
safe to delete).
A) runtime-release.yaml: add a native build-darwin job (macos-14 arm64 /
macos-13 amd64) that builds the dashboard + cross-correct Go API and
publishes xworkspace-console-runtime-darwin-{arm64,amd64}.tar.gz, fixing the
macOS deploy 404. publish now needs both build jobs and globs all runtimes.
B) offline-package workflow: GitHub caps release assets at 2 GiB. Split any
package >= 2 GiB into 1900 MiB parts plus a <name>.parts manifest and upload
the parts. The offline bootstrap (download_offline_split) falls back to the
manifest and reassembles the parts when the single asset is absent. Verified
the split/reassemble round-trips byte-for-byte.
