Replace the 3D menu with a 2D | 3D switch; 3D controls in the dock; 0.6.1

The toolbar button next to Export is now a two-state switch: both
labels are visible and the filled half is the current view, so a
diagram that opens in 2D shows "2D" and one click flips it to 3D. The
dropdown is gone; nothing is greyed out and no menu stays open after a
choice.

The 3D-only controls moved to Archify's bottom-right dock beside PATH
and LENS: STACK (levels by kind, on or off), TOP (from above), and the
zoom stepper's middle button reads RESET while 3D is on, instead of a
2D zoom level that meant nothing there.

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "archify-vscode-ext",
-  "version": "0.6.0",
+  "version": "0.6.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "archify-vscode-ext",
-      "version": "0.6.0",
+      "version": "0.6.1",
       "license": "MIT",
       "dependencies": {
         "three": "^0.186.1",