fix: stabilize runtime follow-up regressions

site/doc/pages/to_json.txt

@@ -0,0 +1,34 @@
+:sig
+String DTree::to_json(char quote_char = '"') const
+
+:params
+quote_char : quote character used around string output
+return value : the scalar as a single JSON token
+
+:see
+>types
+0_DTree
+json_encode
+json_decode
+to_string
+
+:content
+Renders a single scalar `DTree` value as a JSON token. This is a read accessor: it is `const`, never creates or modifies nodes, and dereferences internal references automatically.
+
+Strings are escaped and quoted, numbers render as numeric literals, and booleans render as `true` / `false`.
+
+This is **not** a serializer for nested data: map-shaped nodes render as the placeholder string `"(array)"`. Use `json_encode()` to serialize a whole tree.
+
+## Example
+
+```cpp
+String token = context.props["label"].to_json();   // "\"Don't panic\""
+String body = json_encode(context.props);          // full tree serialization
+```
+
+The `quote_char` parameter exists for embedding output inside single-quoted contexts; for HTML attributes prefer double quotes plus `html_escape()`.
+
+## Related Concepts
+
+- JavaScript: `JSON.stringify(value)` for a single scalar
+- PHP: `json_encode($scalar)`