Add copyable evidence-backed dashboard briefs

[FZ2000]

Effect in one sentence

Adds a secondary Copy review brief action that copies the same recorded facts shown by the Shift Brief without resuming, rerunning, or mutating the Task.

Stack position

3 of 6: #153 → #155 → #157 (this copy layer) → #159 → #160 → #161.

This branch is based on #155, not main; the stack is an alternative to standalone #152.

Copied shape

Review brief
Task: Verify dashboard hierarchy
Task ID: task_…
Recorded attention: Failed check — Snapshot verification failed
Recorded next step: None recorded
Observed: 2026-08-28T04:00:00Z
Provenance: External CI or provider

A brief becomes a Continuation brief only when the daemon explicitly reports handed_off: true.

Truth and safety boundaries

• Copies only recorded task/project/agent identity, attention reason, next step, time, and provenance.
• Missing facts are named; no recovery instruction is invented.
• The pasteboard result—not the tap—determines copied/failed feedback.
• Overlapping copy attempts are tokenized so an old timer cannot clear a newer result.
• Review evidence remains primary; the copy action has a stable footprint and native button hierarchy.

Review order

1. Deterministic brief presentation.
2. Injectable pasteboard boundary and feedback state.
3. Brief-card button hierarchy/accessibility.
4. Interaction tests and four Dashboard references.

Verification at current head 10cbd48

• Current-head GitHub CI passes pytest on Python 3.11/3.12/3.13 and the macOS app/snapshot job.
• Dashboard interaction tests — 23 passed.
• Dashboard snapshot harness — 6 passed.
• Canonical Dashboard references match and were manually inspected.
• Whole-diff audit confirmed native interactive hierarchy, stable feedback width, and clean git diff --check against Build an evidence-first dashboard Shift Brief #155.

Scope

This is deterministic local copy behavior only. It does not send a message, create a handoff, resume an agent, or change daemon state.