Dashboard: make Needs review complete beyond recent tasks

[FZ2000]

Effect in one sentence

Prevents the Dashboard from claiming All clear from only the newest 200 Tasks and prevents a failed refresh from leaving retained attention data looking current.

Review routing

Standalone alternative: choose this PR or the stacked path #153 → #155 → #157 → #159 → #160 → #161. Do not merge both API approaches.

Behavior contract

Situation	Dashboard behavior
Current daemon reports exact attention.total == 0	All clear
Attention exists beyond the recent page	Exact total plus up to two highest-priority rows
Older daemon returns an explicitly complete Task page	Derive from that complete page
Older daemon returns a truncated/unknown page	Review status incomplete
Current refresh fails after earlier success	Review status unavailable; retained success cannot look current

Contract and safety

• Existing Task pagination and Recent Work behavior remain unchanged.
• The additive summary is exact, bounded, and built from the cached all-store visible Task projection without per-Task Receipt requests.
• Open findings and failed evidence lead blockers; settled findings retain history but leave the queue.
• Older clients ignore the new field; the new client treats its absence conservatively.

Review order

1. Python API/reducer and receipt API tests.
2. Swift optional decoding and independent publication.
3. Dashboard state mapping and routing.
4. Canonical Dashboard references.

Verification at current head 2ccd1d4

• Current-head GitHub CI passes pytest on Python 3.11/3.12/3.13 and the macOS app/snapshot job.
• Focused receipt API tests — 17 passed.
• Dashboard interaction tests — 13 passed.
• swift test — 96 executed, 5 expected opt-in visual skips, 0 failures.
• Canonical Dashboard light/dark minimum/reference snapshots match.
• Full local Python suite — 2,638 passed; 9 macOS process-identity failures reproduce on the untouched base, while Linux CI is green.
• git diff --check origin/main...HEAD — clean.

Scope

This proves the Dashboard claim with a two-row preview. It does not redesign or repaginate Work and is intentionally not combined with the dedicated attention-endpoint stack.