Lohnt sich dein eigenes Portfolio Coach?

Build me a local-first UK family portfolio tracker like Portfolio Coach. Requirements:

- Next.js 16 App Router + TypeScript, Tailwind, better-sqlite3, and Recharts;
  run locally with `npm run dev` and bind to localhost only.
- Model household members, accounts, and UK wrappers: ISA, SIPP, GIA, pension,
  cash, bonds, and property with mortgages.
- Holdings need ticker, units, cost basis, currency, manual price, and optional
  market price. Always show the quote source and last-updated time.
- Add a CSV importer with saved column mappings and dedupe on a stable row hash.
  Include a mapping for a documented Vanguard transaction CSV example.
- Dashboard: household net worth, value by person, allocation, wrapper split,
  concentration warnings, gain/loss, and stale-price warnings.
- Add editable monthly contributions and a projection chart with retirement age,
  growth, inflation, withdrawals, and planned gifts as explicit assumptions.
- Add a UK planning page for ISA/SIPP/GIA balances and an indicative inheritance-
  tax snapshot. Keep thresholds in one dated config file and label this as
  informational, not financial or tax advice.
- Add an AI review that sends only the calculated portfolio summary to an
  OpenAI-compatible API. Put secrets in `.env.local`; work without AI too.
- Store everything in one local SQLite file and add an encrypted JSON export plus
  a dated backup command. Include a realistic seeded demo household.
- No accounts, telemetry, broker logins, automatic bank sync, or cloud sharing.
  Out of scope: regulated advice and production-grade real-time fund pricing.
- README with setup, CSV format, backup/restore, data limitations, and the exact
  assumptions used by projections and tax estimates.