Add integration tests for the portfolio analytics flow

[aishagbadamosi]

Adds two integration test suites covering the full dashboard pipeline — account balances → CoinGecko USD estimates → Recharts allocation/performance/risk views → CSV export — 67 tests, all passing.

• tests/integration/portfolioAnalyticsCalculations.test.ts (52 tests) covers every portfolio calculation: USD pricing, unpriced assets, allocation, diversification, concentration, counterparty risk, volatility, Sharpe ratio, P&L, correlation, rebalancing, historical reconstruction, summaries, and CSV row generation.
• tests/integration/portfolioAnalyticsFlow.test.tsx (15 tests) drives the real PortfolioValue component through two-, one-, five-, unpriced-, empty- and disconnected-account portfolios, plus loading, price-API failure, refresh recovery, and Horizon history failure. Only the seams are stubbed — the store, the Horizon server, and Recharts' ResponsiveContainer — so all pricing, analytics, chart and export code under test is production code.

closes #251

Summary

Adds two integration test suites covering the full dashboard pipeline — account balances → CoinGecko USD estimates → Recharts allocation/performance/risk views → CSV export — 67 tests, all passing.

• tests/integration/portfolioAnalyticsCalculations.test.ts (52 tests) covers every portfolio calculation: USD pricing, unpriced assets, allocation, diversification, concentration, counterparty risk, volatility, Sharpe ratio, P&L, correlation, rebalancing, historical reconstruction, summaries, and CSV row generation.
• tests/integration/portfolioAnalyticsFlow.test.tsx (15 tests) drives the real PortfolioValue component through two-, one-, five-, unpriced-, empty- and disconnected-account portfolios, plus loading, price-API failure, refresh recovery, and Horizon history failure. Only the seams are stubbed — the store, the Horizon server, and Recharts' ResponsiveContainer — so all pricing, analytics, chart and export code under test is production code.

Closes #251

How was this tested?

Merge requirements

A PR is merged only when every box below is true. See
Merge requirements for the full policy.

• All required CI checks pass on the latest commit (not just an earlier push).
• No required checks are failing, pending, or skipped — re-run or fix them; do not ask for a merge while any are outstanding.
• The branch has no merge conflicts with the target branch (rebase or merge master if GitHub shows "This branch has conflicts").
• Tests were added or updated for the change (primary flow, a boundary case, and a failure case).
• Docs were updated where behaviour, configuration, or security posture changed.

Security-sensitive changes

• This PR touches a path covered by .github/CODEOWNERS (wallet, auth, cryptography, CI) and a code owner has been requested for review.
• I described any change to key handling, signing, session lifetime, or trusted endpoints above.

[vercel]

@aishagbadamosi is attempting to deploy a commit to the nanle-code's projects Team on Vercel.

A member of the Team first needs to authorize it.