feat: build invoice detail page

[newmattock]

Fixes #12

Summary

• Add /invoices/[id] detail page with invoice field display, lifecycle timeline, and contract event history.
• Wire role-aware actions for connected wallets: payer mark-paid, freelancer cancel, and LP transfer-position entry point.
• Add focused tests for public rendering, payer/freelancer/LP action surfaces, and missing invoice handling.
• Carry narrow current-main build fixes for governance status typing, token selector helper types, and federation account typing.

Validation

• npm test -- 'app/invoices/[id]/__tests__/InvoiceDetailPage.test.tsx' --pool forks --maxWorkers 1 --reporter verbose
• npm run lint -- 'app/invoices/[id]/page.tsx' 'app/invoices/[id]/__tests__/InvoiceDetailPage.test.tsx' src/components/InvoiceStatusTimeline.tsx src/components/InvoiceEventHistory.tsx app/governance/page.tsx src/components/TokenSelector.tsx src/utils/federation.ts
• git diff --check
• npm run build
• curl -I http://127.0.0.1:3032/invoices/1