feat(desktop): attach images to a cloud workspace at create

apps/desktop/src/renderer/routes/_authenticated/components/DashboardNewWorkspaceModal/components/DashboardNewWorkspaceForm/PromptGroup/hooks/useSubmitWorkspace/useSubmitWorkspace.ts

@@ -133,8 +133,9 @@ export function useSubmitWorkspace(
 				// Returns as soon as the row exists — the sandbox is still being
 				// provisioned behind it, which the workspace screen renders.
 				// Same rule as a local create: an agent launches only when there
-				// is something to say to it. Attachments stay behind — they are
-				// written to a host, and this workspace's host doesn't exist yet.
+				// is something to say to it. Attachments were uploaded to cloud
+				// storage rather than a host, so the ids here are `files.id`s the
+				// sandbox resolves and pulls once it is up.
 				const wantCloudAgent =
 					selectedAgent !== "none" &&
 					(!!draft.prompt.trim() ||
@@ -163,6 +164,9 @@ export function useSubmitWorkspace(
 								model: selectedModel ?? undefined,
 								effort: selectedEffort ?? undefined,
 								mode: selectedMode ?? undefined,
+								...(attachmentIds.length > 0
+									? { attachmentFileIds: attachmentIds }
+									: {}),
 							}
 						: {}),
 				});

apps/desktop/src/renderer/routes/_authenticated/components/DashboardNewWorkspaceModal/components/DashboardNewWorkspaceForm/PromptGroup/hooks/useUploadAttachments/index.ts

@@ -1,4 +1,5 @@
 export {
+	CLOUD_UPLOAD_TARGET,
 	type UploadState,
 	useFileIdsForHost,
 	useUploadStateFor,

apps/desktop/src/renderer/routes/_authenticated/components/DashboardNewWorkspaceModal/components/DashboardNewWorkspaceForm/PromptGroup/hooks/useUploadAttachments/store.ts

@@ -1,3 +1,4 @@
+import { apiTrpcClient } from "renderer/lib/api-trpc-client";
 import { getHostServiceClientByUrl } from "renderer/lib/host-service-client";
 import { create } from "zustand";
 import { useShallow } from "zustand/react/shallow";
@@ -21,6 +22,38 @@ export const useAttachmentUploadsStore = create<UploadStoreState>(() => ({
 // observed by React. Keyed identically to entries: outer fileId, inner hostUrl.
 const promiseMap = new Map<string, Map<string, Promise<UploadState>>>();
 
+/**
+ * The target of an upload when there is no host to send it to: a cloud
+ * workspace's sandbox does not exist until after the create. Bytes go to
+ * cloud storage instead, and the id a `ready` entry carries is a `files.id`
+ * the API resolves, not a host attachment id.
+ */
+export const CLOUD_UPLOAD_TARGET = "cloud";
+
+async function fetchBlob(url: string): Promise<Blob> {
+	return await (await fetch(url)).blob();
+}
+
+async function uploadToCloud(file: StartUploadInput): Promise<string> {
+	const blob = await fetchBlob(file.url);
+	const { fileId, upload } = await apiTrpcClient.attachment.createUpload.mutate(
+		{
+			name: file.filename ?? "attachment",
+			contentType: file.mediaType,
+			sizeBytes: blob.size,
+		},
+	);
+	const response = await fetch(upload.url, {
+		method: "PUT",
+		headers: upload.headers,
+		body: blob,
+	});
+	if (!response.ok) {
+		throw new Error(`Upload failed (${response.status})`);
+	}
+	return fileId;
+}
+
 async function fetchBase64(url: string): Promise<string> {
 	if (url.startsWith("data:")) {
 		const commaIndex = url.indexOf(",");
@@ -71,17 +104,21 @@ export function startUpload(hostUrl: string, file: StartUploadInput): void {
 
 	const promise = (async (): Promise<UploadState> => {
 		try {
-			const data = await fetchBase64(file.url);
-			const result = await getHostServiceClientByUrl(
-				hostUrl,
-			).attachments.upload.mutate({
-				data: { kind: "base64", data },
-				mediaType: file.mediaType,
-				originalFilename: file.filename,
-			});
+			const attachmentId =
+				hostUrl === CLOUD_UPLOAD_TARGET
+					? await uploadToCloud(file)
+					: (
+							await getHostServiceClientByUrl(
+								hostUrl,
+							).attachments.upload.mutate({
+								data: { kind: "base64", data: await fetchBase64(file.url) },
+								mediaType: file.mediaType,
+								originalFilename: file.filename,
+							})
+						).attachmentId;
 			const next: UploadState = {
 				kind: "ready",
-				attachmentId: result.attachmentId,
+				attachmentId,
 			};
 			setEntry(file.id, hostUrl, next);
 			return next;

apps/desktop/src/renderer/routes/_authenticated/components/DashboardNewWorkspaceModal/components/DashboardNewWorkspaceForm/PromptGroup/hooks/useUploadAttachments/useUploadAttachments.ts

@@ -16,10 +16,13 @@ export interface UseUploadAttachmentsApi {
 
 /**
  * Drives background attachment uploads. Each file uploads exactly once, to
- * whichever host was active when the user added it; switching hosts does not
- * re-upload. The upload store keys results by `(fileId, hostUrl)` so the
+ * whichever target was active when the user added it; switching targets does
+ * not re-upload. The upload store keys results by `(fileId, target)` so the
  * visible pill list (filtered via `useFileIdsForHost`) follows the picker
- * while previous-host attachments stay cached for return visits.
+ * while previous targets' attachments stay cached for return visits.
+ *
+ * A target is a host URL, or `CLOUD_UPLOAD_TARGET` when the workspace will be
+ * a cloud one and has no host yet.
  */
 export function useUploadAttachments({
 	files,

apps/desktop/src/renderer/routes/_authenticated/components/DashboardNewWorkspaceModal/components/NewWorkspaceScreen/NewWorkspaceScreen.tsx

@@ -84,6 +84,7 @@ import { useBranchPickerController } from "../DashboardNewWorkspaceForm/PromptGr
 import { useLinkedContext } from "../DashboardNewWorkspaceForm/PromptGroup/hooks/useLinkedContext";
 import { useSubmitWorkspace } from "../DashboardNewWorkspaceForm/PromptGroup/hooks/useSubmitWorkspace";
 import {
+	CLOUD_UPLOAD_TARGET,
 	useFileIdsForHost,
 	useUploadAttachments,
 } from "../DashboardNewWorkspaceForm/PromptGroup/hooks/useUploadAttachments";
@@ -525,11 +526,17 @@ export function NewWorkspaceScreen({
 	});
 
 	// ── Submit ───────────────────────────────────────────────────────
+	// A cloud workspace has no host to upload to, so its attachments go to
+	// cloud storage and the sandbox pulls them once it is up.
+	const uploadTarget =
+		(draft.hostId ?? machineId) === CLOUD_HOST_ID
+			? CLOUD_UPLOAD_TARGET
+			: launchHostUrl;
 	const uploadAttachments = useUploadAttachments({
 		files: attachments.files,
-		hostUrl: launchHostUrl,
+		hostUrl: uploadTarget,
 	});
-	const fileIdsForCurrentHost = useFileIdsForHost(launchHostUrl);
+	const fileIdsForCurrentHost = useFileIdsForHost(uploadTarget);
 	const visibleFiles = useMemo(() => {
 		const idSet = new Set(fileIdsForCurrentHost);
 		return attachments.files.filter((file) => idSet.has(file.id));