Expose actionable arXiv digest freshness in the cockpit

[Jammy2211]

Summary

The cockpit now distinguishes stale arXiv digest delivery from overdue human lensing catch-up. Each digest has independent machine-readable freshness, evidence and explicit investigation actions. Quiet days remain healthy; missing, invalid or future stamps are unknown. No remediation runs automatically.

Closes #111.

Scripts Changed

• scripts/board.py: shared digest observations for board and feed; stable IDs, canonical state, UTC observation time, weekday threshold, reason, stamp/workflow evidence and safety-labelled actions.
• tests/test_board.py: weekday boundaries, quiet/backlogged queues, independent digests, unknown evidence, renderer consistency and action metadata.
• README.md: digest state semantics and separation from human catch-up.

Test Plan

• make test: 272 passed.
• make validate: citations, structure and wikilinks pass (no new unresolved links).
• Shared Brain v1 validator accepts healthy, stale and unknown feed fixtures.
• Chromium: mobile/desktop, light/dark, healthy/stale/unknown boards; cockpit actions, evidence links and clipboard; no JavaScript errors.
• Diff review and whitespace check; no library or workflow changes.

Evidence and limits

The date stamp records a digest heartbeat; it is not a workflow run ID or proof all workflow steps succeeded. Read-only actions open the workflow and source stamp; the investigation prompt requires approval. Existing browser-side ageing remains intact. No agent integration or workflow dispatch is added.

Heart readiness

Live user authorization: “I authorize”, in direct response to the request to ship Memory #111 despite Heart RED. This permits commit, push and opening this pending-release PR only; merge and release are not authorized. Current RED: release validation FAILED (stage integrate).
Other reported reasons:

• workspace validation not passing (0 failed, 1 timeout, cloud#36404726969: autolens_test scripts/multi_dataset/rectangular.py)
• manifest drift: public front-door organ tables (generated) — 1 mismatch(es) vs PyAutoMind/repos.yaml

This branch does not claim to repair Heart or bypass CI. Branch gates passed as listed above. Heart verdict timestamp: 2026-10-01T10:39:00.775996+00:00.