Sanitize upon saving

Signed-off-by: Émile Ré <emile@getprobo.com>

e2e/internal/testutil/prosemirror.go

@@ -0,0 +1,40 @@
+// Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package testutil
+
+import (
+	"encoding/json"
+)
+
+// ProseMirrorTextDoc returns minimal ProseMirror/Tiptap JSON accepted by the API:
+// a doc with one paragraph containing a single text node.
+func ProseMirrorTextDoc(text string) string {
+	doc := map[string]any{
+		"type": "doc",
+		"content": []any{
+			map[string]any{
+				"type": "paragraph",
+				"content": []any{
+					map[string]any{"type": "text", "text": text},
+				},
+			},
+		},
+	}
+	b, err := json.Marshal(doc)
+	if err != nil {
+		panic(err)
+	}
+	return string(b)
+}