feat(producer): list public keys from PDS

packages/producer/mod.ts

···
   LocalPublicKey,
   ProducerOptions,
   ProducerParams,
+  PublicKeyOption,
 } from "./types.ts";
 import { type Did, parse, type ResourceUri } from "@atcute/lexicons";
 import type { Client, CredentialManager } from "@atcute/client";
···
 
   /**
    * Lists public keys registered in the user's PDS
-   * @todo List public keys
    */
-  async listPublicKeys() {}
+  async *listPublicKeys(): AsyncIterator<
+    PublicKeyOption,
+    void,
+    void
+  > {
+    let cursor: string | undefined;
+
+    while (true) {
+      const res = await this.rpc.get("com.atproto.repo.listRecords", {
+        params: {
+          collection: "app.cistern.lexicon.item",
+          repo: this.did,
+          cursor,
+        },
+      });
+
+      if (!res.ok) {
+        throw new Error(
+          `failed to list public keys: ${res.status} ${res.data.error}`,
+        );
+      }
+
+      cursor = res.data.cursor;
+
+      for (const record of res.data.records) {
+        const item = parse(AppCisternLexiconPubkey.mainSchema, record.value);
+
+        yield {
+          uri: record.uri,
+          content: item.content,
+          name: item.name,
+        };
+      }
+
+      if (!cursor) return;
+    }
+  }
 
   /**
    * Sets a public key as the main encryption key

packages/producer/types.ts

···
   uri: ResourceUri;
   record: AppCisternLexiconPubkey.Main;
 }
+
+export interface PublicKeyOption {
+  uri: ResourceUri;
+  name: string;
+  content: string;
+}