update changelogs

Author: Swimburger

fern/products/sdks/overview/typescript/changelog/2025-10-14.mdx

@@ -0,0 +1,34 @@
+## 3.9.0
+**`(feat):`** Add support for the `Uploadable.FromPath` and `Uploadable.WithMetadata` types to upload files with metadata to multipart-form endpoints.
+
+Users can configure metadata when uploading a file to a multipart-form upload endpoint using the `Uploadable.WithMetadata` type:
+```typescript
+import { createReadStream } from "fs";
+
+await client.upload({
+    file: {
+      data: createReadStream("path/to/file"),
+      filename: "my-file",
+      contentType: "audio/mpeg",
+    },
+    otherField: "other value",
+});
+```
+The `filename`, `contentType`, and `contentLength` properties are optional.
+
+Alternatively, users can use the `Uploadable.FromPath` type to upload directly from a file path:
+```typescript
+await client.upload({
+    file: {
+        path: "path/to/file",
+        filename: "my-file",
+        contentType: "audio/mpeg",
+    },
+    otherField: "other value",
+});
+```
+
+The metadata is used to set the `Content-Type` and `Content-Disposition` headers. If not provided, the client will attempt to determine them automatically.
+```
+
+