Add durable native capture outbox

[Clearner1]

Summary

• add an internal /api/captures durable SQLite outbox on the existing API process
• return 202 after SQLite commit and process native memo/Q&A asynchronously into Anki
• add UUID idempotency, atomic worker claims, retry/unknown-write states, and restart recovery
• distinguish Anki transport errors from action/configuration errors

Checks

• Vitest: 19 server tests + 4 AnkiConnect tests
• ESLint
• strict TypeScript source check
• Node strip-types startup smoke test

The Caddy/mTLS route is intentionally not part of this PR and will be configured only after review.