The radar reads upstream releases on a schedule and files an issue when an update is worth taking, with the reason and the risk #9592

From #9434 box 3. src/flows/radar.ts exists and runs when an admin asks.

Done looks like:

• [x] The radar runs on a schedule (nightly by default) for every repository with pinned packages.
• [x] A release worth taking files one issue per dependency (never a duplicate while one is open), saying in plain words what changed, why it is useful and what could break.
• [x] On an autonomous repository the issue goes to the crew; otherwise it waits for a person.
• [x] Tests with a fake registry: a new release files one issue, a second run files none.

Files: src/flows/radar.ts, src/nightly/, test/.

Reviewed pull #9609 at its head: ticked The radar runs on a schedule (nightly by default) for every repository with pinned packages.; A release worth taking files one issue per dependency (never a duplicate while one is open), saying in plain words what changed, why it is useful and what could break.; On an autonomous repository the issue goes to the crew; otherwise it waits for a person.; Tests with a fake registry: a new release files one issue, a second run files none..