[Code scan] Block JSON export when required fields are invalid

[njzjz]

This issue was found during a Codex global code scan of the repository.

Baseline commit: e3c5b38

Problem

The Save JSON button calls to_json() directly. Vuetify field rules can show validation errors, but export is not gated on validation state. Empty required values are silently converted into defaults by dvalue().

Code references:

dpgui/src/components/dargs/DargsInput.vue

Lines 27 to 28 in e3c5b38

	<v-btn block @click="to_json()">
	{{ $t("message.save_json") }}

dpgui/src/components/dargs/DargsItem.vue

Lines 329 to 345 in e3c5b38

	// textarea -> list
	if (!this.value) return [];
	return this.value
	.trim()
	.split("\n")
	.map((v) => {
	try {
	return JSON.parse(v);
	} catch (e) {
	return v;
	}
	});
	}
	} else if (["str", "int", "float"].includes(this.select_type)) {
	if (!this.value) {
	if (this.select_type == "str") return "";
	else return 0;

Relevant snippet:

if (!this.value) return [];

if (!this.value) {
  if (this.select_type == "str") return "";
  else return 0;
}

Impact

Users can export JSON even when required fields are empty or invalid. The exported file can contain [], "", or 0 values that were never intentionally supplied.

Suggested fix

Wrap the generated controls in a v-form, validate before to_json(), and avoid substituting empty required fields with default-looking values during export.