feat(web): persist browser state

Keep settings, aliases, and recent drawings across browser sessions.

Load Start-page videos from a Pages-generated snapshot.

web/videos.json

@@ -0,0 +1,22 @@
+[
+  {
+    "id": "QFDMSRNrZOU",
+    "title": "Create 2D Chair DWG Drawing in Open CAD Studio"
+  },
+  {
+    "id": "bHwKKOdBtCQ",
+    "title": "Open CAD Studio: Object Snap Explained"
+  },
+  {
+    "id": "JRlmIInZRiQ",
+    "title": "How to Install Open CAD Studio – Free DWG Authoring Tool"
+  },
+  {
+    "id": "4_glyJFo0qI",
+    "title": "Open CAD Studio as a Free DWG File Viewer with No Login Needed"
+  },
+  {
+    "id": "uN9zxM7p_fc",
+    "title": "Open CAD Studio Tutorial: Create a 2D DWG Drawing & Export to PDF"
+  }
+]