Add evidence freshness metadata and prioritize the current project brief #216

Requested after the WordsApp audit on 2026-09-13: historical pending-deployment reports, later successful deployments and dated DNS observations compete in recall. A current brief and reconciliation help, but the brief is below newer notes and duplicated user preferences consume the context budget.

Implementation idea:

• Define observedAt/lastVerifiedAt and evidence references separately from CreatedAt/UpdatedAt/expiresAt. Editing prose must not imply verification.
• Reserve recall space for the current approved project brief, then relevant decisions and evidence; present session reports as dated history.
• Distinguish historical events from time-sensitive current-state claims and expose verification limits. Preserve valuable history.
• Reuse design tasks #77/#97/#98. Specify migration defaults for unknown verification dates and consistent UI/MCP fields.

Acceptance criteria:

• Editing an old observation does not make it freshly verified.
• Evaluate deployment-pending then deployed, fixed defects, stale DNS, conflicting guidance and unverified release status against #98's baseline.
• The brief and essential evidence remain discoverable under bounded budgets.
• Evidence links preserve permissions; no automatic external checks, publication or paid background service is added.

Memory-MCP audit evidence (2026-09-13)

The imported brief #142 describes the local SQLite component while newer hosted behavior lives in session summaries. Active decisions #170 and #189 contradict #182 and #196. Editing prose or importing memories must not count as fresh technical verification. Include these cases, duplicate personal guidance and explicit local-versus-hosted applicability in the #98 evaluation. Evidence: docs/memory-freshness-review-2026-09-13.md.