feat: optimize checkphrase processing

[dewabisma]

No description provided.

[n13]

Reviewer model: GPT-6 Astra

APPROVE — no blocking findings at a0029095db3241ae5beab040b4d8f28dbc7ec08f (base 6861302d4e795aa88e66b90cadcac9f3de2f7951).

Reviewed the complete diff, including the packaged checksum upgrade, worker serialization and failure handling, shared-address cancellation, caching, visibility gating, and both hook consumers. The derivation parameters and word list remain compatible with existing cached phrases.

Validation:

• Frozen-lockfile dependency installation succeeded with lifecycle scripts disabled.
• bun test src/utils/get-checksum.test.ts src/utils/checksum-phrase.test.ts src/components/ui/composites/account-address-cell/AccountAddressCell.test.tsx: 19 passed, 0 failed.
• bun run build: Vite production build and TypeScript check passed.
• The actual production worker ran in Chromium and matched the previous 0.3.0 derivation for all 32 tested inputs.
• git diff --check passed; both GitHub checks passed. The CI job named “Build and Test” currently runs the build, not unit tests.

Browser validation covered Chromium; physical-device Safari was not tested.