Handle missing LP redeemed amounts

[vku2018]

Summary

• make LP redeemed amount formatting tolerate null, undefined, and invalid raw values
• allow LPPosition data to omit redeemed amounts and token symbols without rendering undefined or NaN
• fall back to stable TOKEN_0 / TOKEN_1 labels when token symbols are missing
• add component coverage for partial LP data and formatter coverage for nullish raw amounts

Why

Partial LP API responses can omit redeemed amounts or token labels. The previous rendering path sent those values directly into display helpers, which could expose broken UI text or throw from token rendering. This keeps the LP card stable when data is incomplete.

Closes #53.

Validation

• npm run test -- __tests__/components/LPPosition.test.tsx __tests__/lib/format.test.ts
• npm test -- --runInBand (28 tests passed)
• npm run lint -- components/LPPosition.tsx lib/format.ts __tests__/components/LPPosition.test.tsx __tests__/lib/format.test.ts
• npm run typecheck
• git diff --check