Show right widget sidebar at iPad-landscape width

The right sidebar previously required xl (1280px) to appear, so horizontal
iPad (1024px) viewports saw only the left sidebar + main column. Use the
existing lg breakpoint (1024px) to control right-sidebar visibility, and
let the sidebars scale fluidly with the viewport by setting them to w-1/4
max-w-[300px] instead of fixed pixel widths. The center column (flex-1)
absorbs whatever space remains, so the layout fills the viewport smoothly
from 1024px up through the 1200px wrapper cap instead of leaving dead
space at intermediate widths. Below the lg breakpoint, the left sidebar
keeps its fixed 300px width.

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "ditto",
-  "version": "2.11.2",
+  "version": "2.12.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "ditto",
-      "version": "2.11.2",
+      "version": "2.12.0",
       "dependencies": {
         "@bitcoinerlab/secp256k1": "^1.2.0",
         "@capacitor/app": "^8.0.0",