chore: import upstream snapshot with attribution

apps/sim/lib/uploads/client/api-fallback.ts

@@ -0,0 +1,42 @@
+import type { StorageContext } from '@/lib/uploads/shared/types'
+
+/**
+ * Server-proxied fallback used only when cloud storage isn't configured (local dev).
+ * Production always takes the presigned PUT path.
+ */
+export async function uploadViaApiFallback(
+  file: File,
+  context: StorageContext,
+  workspaceId?: string
+): Promise<{ path: string; key?: string }> {
+  const formData = new FormData()
+  formData.append('file', file)
+  formData.append('context', context)
+  if (workspaceId) {
+    formData.append('workspaceId', workspaceId)
+  }
+
+  // boundary-raw-fetch: local-dev fallback when cloud storage is not configured; multipart upload incompatible with requestJson
+  const response = await fetch('/api/files/upload', { method: 'POST', body: formData })
+  if (!response.ok) {
+    const errorData = (await response.json().catch(() => ({}))) as {
+      message?: string
+      error?: string
+    }
+    throw new Error(
+      errorData.message || errorData.error || `Failed to upload file: ${response.status}`
+    )
+  }
+  const data = (await response.json()) as {
+    fileInfo?: { path?: string; key?: string }
+    path?: string
+    key?: string
+    url?: string
+  }
+  const path = data.fileInfo?.path ?? data.path ?? data.url
+  const key = data.fileInfo?.key ?? data.key
+  if (!path) {
+    throw new Error('Invalid upload response: missing path')
+  }
+  return { path, key }
+}