fix: reduce longtext size to fit within INT column limit

The size field in the attributes collection is stored as a signed 32-bit
integer (VAR_INTEGER). The longtext size of 4294967295 (2^32-1) exceeds
the maximum value of 2147483647 (2^31-1), causing attribute creation to
fail with a 400 error (document_invalid_structure).

Changed the longtext size to 2147483647 which is the maximum value that
fits within the signed 32-bit integer constraint of the schema.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/Appwrite/Platform/Modules/Databases/Http/Databases/Collections/Attributes/Longtext/Create.php

@@ -89,7 +89,7 @@ class Create extends Action
             new Document([
                 'key' => $key,
                 'type' => Database::VAR_LONGTEXT,
-                'size' => 4294967295,
+                'size' => 2147483647,
                 'required' => $required,
                 'default' => $default,
                 'array' => $array,