feat: adopt shared dashboard freshness footer

[Jammy2211]

Summary

Adopt the shared small Last updated footer beside Read the prompt, using owner collection metadata and an Update link to the existing refresh workflow. Preserve domain evidence and health meanings.

Refs PyAutoLabs/PyAutoBrain#486. This is one coordinated eleven-repository change covering thirteen boards; human merge follows Brain-first ordering. Publication has not yet been verified.

API Changes

None — internal board presentation changes only.

Test Plan

• 74 tests verified for PyAutoEars.
• Browser witness: 120 current layout cases across all thirteen boards and degraded state, plus 14 copy regression cases. Checks include exact 1h/24h boundaries, invalid/future/timezone stamps, native disclosure, live clock, mobile/desktop/light/dark, expanded preview and clipboard invariants.
• Verify published dashboards after authorized merges.

Full API Changes (for automation and release notes)

• Migration: uses the Brain shared freshness footer merged as feat: add shared dashboard freshness footer PyAutoBrain#487. No scientific library API or evidence schema changes.

Heart gate: user invoked /prm in direct response to the disclosed canonical YELLOW warning (shared-standards blocks: 2 manifest mismatches), authorizing ship and green-CI merge. Release evidence remains stale; no release authorized.