feat: create atproto oauth login

src/modules/atproto/service/getFollows.ts

@@ -0,0 +1,24 @@
+export const getFollows = async (did: string): Promise<Set<string>> => {
+  const follows = new Set<string>()
+  let cursor: string | undefined
+
+  do {
+    const url = new URL('https://public.api.bsky.app/xrpc/app.bsky.graph.getFollows')
+    url.searchParams.set('actor', did)
+    url.searchParams.set('limit', '100')
+    if (cursor) {
+      url.searchParams.set('cursor', cursor)
+    }
+
+    const response = await fetch(url)
+    const result: { follows: { did: string }[]; cursor?: string } = await response.json()
+
+    for (const follow of result.follows) {
+      follows.add(follow.did)
+    }
+
+    cursor = result.cursor
+  } while (cursor)
+
+  return follows
+}