fix: replace image/* wildcard with explicit supported types in file picker

The image/* accept attribute allowed users to select BMP, TIFF, HEIC,
and other image types that are rejected server-side. Replace with the
exact set of supported image MIME types and extensions to match the
copilot upload validation.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: waleedlatif1

apps/sim/lib/uploads/utils/validation.ts

@@ -111,7 +111,21 @@ export const ACCEPTED_FILE_EXTENSIONS = SUPPORTED_DOCUMENT_EXTENSIONS.map((ext)
 
 export const ACCEPT_ATTRIBUTE = [...ACCEPTED_FILE_TYPES, ...ACCEPTED_FILE_EXTENSIONS].join(',')
 
-export const CHAT_ACCEPT_ATTRIBUTE = [ACCEPT_ATTRIBUTE, 'image/*'].join(',')
+const SUPPORTED_IMAGE_MIME_TYPES = [
+  'image/jpeg',
+  'image/png',
+  'image/gif',
+  'image/webp',
+  'image/svg+xml',
+]
+
+const SUPPORTED_IMAGE_EXTENSIONS = ['.jpg', '.jpeg', '.png', '.gif', '.webp', '.svg']
+
+export const CHAT_ACCEPT_ATTRIBUTE = [
+  ACCEPT_ATTRIBUTE,
+  ...SUPPORTED_IMAGE_MIME_TYPES,
+  ...SUPPORTED_IMAGE_EXTENSIONS,
+].join(',')
 
 export interface FileValidationError {
   code: 'UNSUPPORTED_FILE_TYPE' | 'MIME_TYPE_MISMATCH'