fix: use plc.directory instead of plc.wtf for DID resolution

The plc.wtf mirror is returning HTTP 502, breaking the static build
when getStaticPaths fetches the PDS endpoint. plc.directory is the
canonical PLC directory and returns the same JSON shape.

src/api/fetch-notes.ts

@@ -8,7 +8,7 @@ export const getServiceEndpoint = async () => {
   if (serviceEndpoint) {
     return serviceEndpoint
   }
-  const response = await fetch(`https://plc.wtf/${did}`)
+  const response = await fetch(`https://plc.directory/${did}`)
   const {
     service: [{ serviceEndpoint: endpoint }],
   } = await response.json()