Add batch upload APIs for truly parallel file uploads

The old upload flow spawned 2 `npx convex run` subprocesses per file
(generateUploadUrl + recordAsset), each taking ~2-3s startup overhead.
For 16 files that's 32 subprocess calls, effectively serial despite
the concurrency pool.

New flow uses batch functions:
1. One `generateUploadUrls` call → N URLs (1 subprocess)
2. Upload all files via fetch in parallel (0 subprocesses)
3. One `recordAssets` call → record all (1 subprocess)

Total: 3 subprocess calls instead of 2N+1.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: sethconvex

dist/cli/upload.js

@@ -61,6 +61,24 @@ export declare function exposeUploadApi(component: ComponentApi): {
         deleted: number;
         blobIds: string[];
     }>>;
+    /**
+     * Generate multiple signed upload URLs in one call.
+     * Much faster than calling generateUploadUrl N times.
+     */
+    generateUploadUrls: import("convex/server").RegisteredMutation<"internal", {
+        count: number;
+    }, Promise<string[]>>;
+    /**
+     * Record multiple uploaded assets in one call.
+     */
+    recordAssets: import("convex/server").RegisteredMutation<"internal", {
+        assets: {
+            path: string;
+            contentType: string;
+            deploymentId: string;
+            storageId: string;
+        }[];
+    }, Promise<void>>;
     /**
      * List all static assets (for debugging).
      */

dist/cli/upload.js.map

@@ -11,7 +11,7 @@ declare const _default: import("convex/server").SchemaDefinition<{
         blobId: import("convex/values").VString<string | undefined, "optional">;
         contentType: import("convex/values").VString<string, "required">;
         deploymentId: import("convex/values").VString<string, "required">;
-    }, "required", "blobId" | "path" | "contentType" | "deploymentId" | "storageId">, {
+    }, "required", "path" | "blobId" | "contentType" | "deploymentId" | "storageId">, {
         by_path: ["path", "_creationTime"];
         by_deploymentId: ["deploymentId", "_creationTime"];
     }, {}, {}>;

dist/client/index.d.ts

@@ -6,7 +6,7 @@ import {
 
 // Expose the upload API as INTERNAL functions.
 // These can only be called via `npx convex run` - not from the public internet.
-export const { generateUploadUrl, recordAsset, gcOldAssets, listAssets } =
+export const { generateUploadUrl, generateUploadUrls, recordAsset, recordAssets, gcOldAssets, listAssets } =
   exposeUploadApi(components.selfHosting);
 
 // Expose the deployment query for live reload notifications.