Load TEE registry through API route

[0xadvait]

Summary

• route TEE registry overview reads through a Next API endpoint so browser clients receive the real on-chain registry data
• split shared registry types/API-client helpers from the server-only contract reader so browser UI no longer imports the ethers/provider module
• serialize bigint fields for JSON and hydrate them back for existing UI formatting
• keep disabled historical registry records behind an explicit toggle so the UI does not present raw record counts like 80/81 as expected TEEs
• clean homepage TEE summaries and live-operator preview to render active operators from live registry data without hardcoded TEE counts, IDs, endpoints, preview caps, fake placeholder values, or percentage/progress-bar calculations

Verification

• yarn eslint lib/opengradient/teeRegistry.ts lib/opengradient/contracts/teeRegistry.ts pages/api/opengradient/tee-registry.ts ui/home/TrustedExecution.tsx ui/home/HeroBanner.tsx ui/opengradient/teeRegistry/TEETypeCard.tsx ui/opengradient/teeRegistry/TEENodesTable.tsx ui/opengradient/teeRegistry/TEENodeDetailDrawer.tsx ui/opengradient/teeRegistry/placeholders.ts ui/pages/opengradient/TEERegistry.tsx
• yarn tsc -p ./tsconfig.json --noEmit
• curl http://localhost:3010/api/opengradient/tee-registry returns 3 active / 3 enabled TEEs
• targeted source scan found no hardcoded active TEE count, TEE IDs, endpoint IPs, old slash-count values, fake placeholder registry types/counts, activePct/primaryActivePct, hardcoded 3-row TEE preview cap, typeof window branch, console logs, or eslint suppressions in touched files
• browser verified homepage renders active operators from /api/opengradient/tee-registry and no fake placeholder text or TEE slash counts