release-update-downstream-packageslisted

# Update Downstream Packages A release of one of the user's packages just published. Find every repo of theirs that consumes it, bump the pin (and sibling workspace packages released together with it), refresh lockfiles, commit, push to trunk, and verify CI end to end. Arguments: $ARGUMENTS This command **pushes to trunk of many repos**. Nothing is mutated before the Phase 3 confirmation gate. `--no-push` runs the whole procedure but leaves commits local. --- ## Phase 1: Inputs and Pre-flight 1. **Package** — the first non-flag argument. If missing, ask. 2. **Version** — the second non-flag argument, or discover the latest published version from the package index (for PyPI: `https://pypi.org/pypi/<package>/json`; for npm: `npm view <package> version`). Confirm the version actually exists on the index before touching anything — locking against an unpublished version fails everywhere at once. 3. **Workspace roots** — from `--roots` globs. If not given, ask the user which directories hold their open-source checkouts (e.g. glob patterns two levels deep under a work directory). Do not assume a layout. 4. **Sibling packages** — if the package is developed in a workspace repo that publishes several packages versioned together, list the siblings (from the source repo's `packages/*` manifests or the index). They bump together. 5. **Fresh resolver cache** — for Python consumers, run `uv cache clean --force` once before any locking, so every loc