Initial commit: dashboard-elements-ui library

Angular library providing dashboard components including grid layout,
drag-and-drop widgets, resize handles, toolbar, config panel, layout
presets, and persistence services.

demo/tsconfig.app.json

@@ -0,0 +1,9 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "./out-tsc/app",
+    "types": []
+  },
+  "files": ["src/main.ts"],
+  "include": ["src/**/*.d.ts"]
+}