Chrome screenshots can be saved for the human

hands/Sources/byre-hands/Chrome.swift

@@ -728,5 +728,8 @@ func chromeTool(_ args: [String: Any]) async throws -> [Content] {
     let shot = try await c.send("Page.captureScreenshot", ["format": "png"], session: t.session)
     let (png, shotNote) = try shrink(Data(base64Encoded: shot.string("data") ?? "") ?? Data(), maxEdge)
     log.append(shotNote)
+    if args.bool("save") {
+        log.append("saved to \(try save(png))")
+    }
     return [.text(log.joined(separator: "\n")), .png(png)]
 }

hands/Sources/byre-hands/Screen.swift

@@ -139,10 +139,14 @@ func captureTool(_ args: [String: Any]) async throws -> [Content] {
     guard args.bool("save") else {
         return [.text(shot.note), .png(shot.png)]
     }
+    return [.text("\(shot.note); saved to \(try save(shot.png))"), .png(shot.png)]
+}
+
+func save(_ png: Data) throws -> String {
     guard let dir = mediaDir else {
         throw ToolError("save needs byre's media folder, and this byre-hands has none")
     }
     let url = URL(filePath: dir).appending(path: "capture-\(UUID().uuidString.prefix(8).lowercased()).png")
-    try shot.png.write(to: url)
-    return [.text("\(shot.note); saved to \(url.path)"), .png(shot.png)]
+    try png.write(to: url)
+    return url.path
 }

hands/Sources/byre-hands/Tools.swift

@@ -123,7 +123,8 @@ let tools: [Tool] = [
             "wait_ms": {"type": "integer", "description": "Wait this long after the op, before wait_for and capture."},
             "timeout_ms": {"type": "integer", "description": "How long navigate waits for the load (default 15000) and wait_for waits (default 10000). Giving up is reported, not an error."},
             "capture": {"type": "boolean", "description": "Finish with a screenshot of the tab's page."},
-            "max_edge": {"type": "number", "description": "Longest edge of the screenshot in pixels, 16 to 8192 (default 1568, which is as much as you can see)."}
+            "max_edge": {"type": "number", "description": "Longest edge of the screenshot in pixels, 16 to 8192 (default 1568, which is as much as you can see)."},
+            "save": {"type": "boolean", "description": "With capture, also save the screenshot as a PNG in the task's media folder; the reply gives its path, which a Markdown image in your final message can show."}
         }, "required": ["op"]}
         """,
         run: chromeTool