[Jason3S]

Adds a weekly workflow that updates the pnpm version pinned in package.json and opens a PR with the change.

The steps live in the shared workflow in streetsidesoftware/actions, callable at @v1 since release 1.7.0. This repo only holds the triggers:

• Mondays at 12:00 UTC.
• Manual dispatch.

What to expect

• This repo pins pnpm 11.27.0. The first bot PR is therefore a major-version jump to pnpm 12, because pnpm self-update goes to latest. On a pnpm 11 lockfile it also adds a second YAML document that records the pnpm version.
• The shared workflow waits two days before it picks up a new pnpm release, the same as minimumReleaseAge in this repo's pnpm-workspace.yaml.
• The packageManager field loses its +sha512… suffix. The lockfile still holds the integrity hashes of the pnpm packages.

Verification

• The same caller runs in six other streetsidesoftware repos.
• Not run in this repo yet. GitHub only offers manual dispatch once the workflow file is on main, so the first run comes after this PR is merged.