[castrojo]

Scoped review follow-up

Two safety corrections; metric definitions, GitHub queries, contributor counts, chart presentation, and the tracked snapshot are unchanged.

• The write-failure CLI regression runs unmodified copied modules and a fixture seed in a disposable workspace. No fault-injected child can overwrite tracked production data, regardless of temporary filename changes.
• The fetcher remains exit 0 for builds. A separate final scheduled-job gate requires a complete, available snapshot generated during the current collection interval; unavailable, retained, stale, or future snapshots make the job red. Genuine measured zero passes.
• Unavailable state is published for review before the final job gate fails. Last-good history and timestamp remain intact.
• Relevant procedure updated in this same PR. No new dependencies or credentials.

Verified

• Actual CLI/workflow-command smoke: unavailable fetcher exit 0; scheduled validation exit 1; last-good total and timestamp retained; verified-zero validation exit 0.
• All complete affected regression modules pass.
• just check passes: 1,354 tests, typecheck, and zero lint errors (existing warnings remain).
• Action 40146255069 used github.token and executed the new Require a verified current refresh step successfully after a real complete collection.
• Main deployment 40147170574 succeeded for aeaa309.
• Cache-busted live analytics check: 456 shown, two chart canvases rendered, old merge-rate metrics absent.