v2.8.1 — the attestation chain lands whole (update from 2.8.0)

If you are on v2.8.0, update now. v2.8.0 shipped with attestation-chain recording broken — every paper fill on it failed to append to your local attestation chain, with the honest "could not be added to the verification chain" toast firing each time (the failure was visible; the chain simply could not record). Your wallet, balances and P&L were never affected, and legacy chains were frozen untouched — migration failed before writing, so nothing was lost. On v2.8.1 recording resumes, and the verify panel will honestly show the v2.8.0-window gap rather than pretend it is not there.

The attestation chain grew up (F-14).

• Single-writer segmented store: a fill rewrites one small tail segment, not the whole history — O(bounded) forever.
• Multi-tab chain races are gone (all appends serialize through the worker).
• Backups are downgrade-safe: a new backup restores intact on a pre-segmentation build (the chain rides in both formats).
• Resets clear the chain atomically with the wallet; no hash is ever truncated; the leaderboard verifier format is unchanged.

Also, credit where due: v2.8.0 quietly contained the Turbo receipts card — Settings now counts your warm vs cold opens, median background routing latency (not page-ready time), and per-site main-thread stalls. Measured locally, stored locally, never sent anywhere.

Suite: 867/867. SHA-256 in SHA256SUMS.txt.