fix(flowchart): replace window.prompt/confirm with inline modal in standalone window; v4.9.9

Electron renderer contexts return undefined from window.prompt/window.confirm,
so shape change, edge kind, edge label, and reset confirmation did nothing.
Bundle now ships promptInline/confirmInline (custom DOM overlay modals) and
uses them in onEdgeClick / onShapeMenu / reset handler. Exposed as
window.FlowchartModals for jsdom tests.

Amit Haridas

package.json

@@ -1,6 +1,6 @@
 {
   "name": "markdown-converter",
-  "version": "4.9.8",
+  "version": "4.9.9",
   "description": "Professional Markdown editor and universal file converter with PDF editing, batch processing, and syntax highlighting",
   "main": "src/main.js",
   "scripts": {