file download actor

README.md

@@ -208,6 +208,43 @@ print((nb as NeighborsResult).neighbors['NORTH']); // u09tunu
 
 ---
 
+## FileDownloadActor
+
+Downloads a file from a URL and saves it to disk via an injected `FileActor`.
+
+```dart
+final actor = FileDownloadActor(
+  fileActor: FileActor(),
+);
+```
+
+| Parameter | Type | Default | Description |
+|---|---|---|---|
+| `fileActor` | `FileActor` | required | Actor used to write the downloaded bytes to disk |
+| `httpClient` | `http.Client?` | new client | Injectable HTTP client; provide a `MockClient` in tests |
+
+Call `actor.close()` when done to release the HTTP client.
+
+| Message | Result | Description |
+|---|---|---|
+| `DownloadFile(url, savePath)` | `FileDownloaded(savePath)` | GETs the URL and writes the response bytes to `savePath`. Throws if the response status is not 2xx. |
+
+```dart
+final actor = FileDownloadActor(fileActor: FileActor());
+
+final result = await actor.handle(
+  const DownloadFile(
+    url: 'https://example.com/image.jpg',
+    savePath: '/tmp/image.jpg',
+  ),
+);
+print((result as FileDownloaded).savePath); // /tmp/image.jpg
+
+await actor.close();
+```
+
+---
+
 ## FileUploadActor
 
 Uploads files to a Nostr-authenticated remote storage service. Handles