Green: filter isDeleted tombstones out of listCollections

src/client.ts

@@ -155,17 +155,21 @@ export class Client {
         const { collections } = await this.api.getJSON<{
             collections: RawCollection[];
         }>("/collections/v2", { sinceTime: 0 });
-        return collections.map((raw) =>
-            decryptCollection(
-                raw,
-                {
-                    masterKey: this.masterKey,
-                    publicKey: this.publicKey,
-                    secretKey: this.secretKey,
-                },
-                this.userID,
-            ),
-        );
+        // The sync API keeps returning deleted collections as tombstones
+        // (isDeleted: true); their diff endpoint 404s, so drop them.
+        return collections
+            .filter((raw) => !raw.isDeleted)
+            .map((raw) =>
+                decryptCollection(
+                    raw,
+                    {
+                        masterKey: this.masterKey,
+                        publicKey: this.publicKey,
+                        secretKey: this.secretKey,
+                    },
+                    this.userID,
+                ),
+            );
     }
 
     async listFiles(