fix(vanta): keep mimeType an ordinary upload parameter

`mimeType` was marked hidden, but `visibility: 'hidden'` is reserved for
system-injected params such as OAuth tokens. It also left the base64 upload path
with no way to set a content type, since `fileContent` is hidden too.

Author: waleedlatif1

apps/docs/content/docs/en/integrations/vanta.mdx

@@ -331,6 +331,7 @@ Upload an evidence file to a Vanta document. Requires credentials with the vanta
 | `documentId` | string | Yes | Unique ID of the document to attach the file to |
 | `file` | file | No | The evidence file to upload |
 | `fileName` | string | No | Optional file name override |
+| `mimeType` | string | No | MIME type of the file \(e.g., application/pdf\). Applies only to the base64 upload path; a file from the File input always sends the content type resolved from storage. |
 | `description` | string | No | Description of the uploaded evidence \(e.g., "Q3 access review evidence"\) |
 | `effectiveAtDate` | string | No | ISO 8601 date indicating when the document is effective from |
 

apps/sim/tools/generated/tool-metadata.ts

@@ -15,6 +15,14 @@ describe('Vanta internal tool declarations', () => {
     }
   })
 
+  it('leaves mimeType an ordinary operation parameter the base64 path can set', () => {
+    expect(vantaUploadDocumentFileTool.params.mimeType.visibility).toBe('user-or-llm')
+  })
+
+  it('hides only the system-injected file content', () => {
+    expect(vantaUploadDocumentFileTool.params.fileContent.visibility).toBe('hidden')
+  })
+
   it('preserves resolved secrets, variables, and protected file references verbatim', () => {
     const file = { key: 'workspace/file.txt', name: 'file.txt', size: 4 }
     expect(

apps/sim/tools/vanta/operation-input.test.ts

@@ -62,7 +62,7 @@ export const vantaUploadDocumentFileTool: InternalToolConfig<
     mimeType: {
       type: 'string',
       required: false,
-      visibility: 'hidden',
+      visibility: 'user-or-llm',
       description:
         'MIME type of the file (e.g., application/pdf). Applies only to the base64 upload path; a file from the File input always sends the content type resolved from storage.',
     },