Repo transfer, step two: git over HTTPS and SSH, running runs, previews and forks follow a moved repository #570

Part of the repo transfer. Comes after step one.

Acceptance:

• [x] git smart-HTTP under the old path is served from the new location (or 308s, which git follows); a git fetch against the old remote works in a test
• [x] SSH under the old path serves the repo and prints the new remote on stderr once
• [x] queued runs point at the new path; a running run finishes or is requeued against it. Running previews are restarted under the new name
• [x] forks and following links keep their parent; tokens scoped to the repo keep working
• [x] a test moves a repo with a fork, a running preview and a queued run, then exercises each

Files: src/git/, src/ssh/, src/runs/*, src/apps/runtime.ts, test/repo-transfer.test.ts. Fits: torque.

Released from Later to use the week's subscription: Behind pace: 75% of the week left with 22% of its time gone, reset 2026-11-15 02:00 UTC, burning 0% an hour against 0.5% allowed; speeding up to 5 of 5 slots and releasing the next issue.

Reviewed pull #10204 at its head: ticked git smart-HTTP under the old path is served from the new location (or 308s, which git follows); a git fetch against the old remote works in a test; SSH under the old path serves the repo and prints the new remote on stderr once; queued runs point at the new path; a running run finishes or is requeued against it. Running previews are restarted under the new name; forks and following links keep their parent; tokens scoped to the repo keep working; a test moves a repo with a fork, a running preview and a queued run, then exercises each.