[mrubens]

Problem

#3613 let runs without an environment fall back to their own repository's GitHub installation when their stamped repositories span installations. All-repository runs (for example custom automations scoped to every repository) have no repository of their own (repo: __all_repositories__), so they still threw GitHubInstallationSpanError and failed to start with a source-control token error.

Change

When an all-repository run without an environment spans installations, anchor the primary token on the deployment's oldest active installation among the stamped repositories, the same installation unconnected reads already use. With #3614, repositories on the other installations still get their own per-repository git credentials.

Validation

• @roomote/github task-run-token.test.ts (26 passed, new all-repository case)
• @roomote/github type check

[roomote-community]

No code issues found. See session

Reviewed installation selection, stamped-repository token scoping, worker per-repository credentials, and the regression test. Current-head tests, lint, type checks, and Knip passed; Docker build, upgrade compatibility, and JavaScript/TypeScript CodeQL were still running when checked.

_{Reviewed 27c08f8}