feat(release): make the signing-free install work with nothing but Windows

The manual install path still needed 7-Zip, which the target machine does not
have, so "installable without a certificate" was not yet true.

The channel now also publishes the app as byte-split zip parts, and the install
script joins them and extracts with the built-in Windows Expand-Archive after
verifying every part and the joined archive. Version 1.3.1 republishes the
channel from a single build, because a version's artifacts can only match one
build and published volumes are never overwritten.

site/package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "d3ro-voice-site",
-  "version": "1.3.0",
+  "version": "1.3.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "d3ro-voice-site",
-      "version": "1.3.0",
+      "version": "1.3.1",
       "dependencies": {
         "react": "^19.0.0",
         "react-dom": "^19.0.0"

site/package.json

@@ -1,7 +1,7 @@
 {
   "name": "d3ro-voice-site",
   "private": true,
-  "version": "1.3.0",
+  "version": "1.3.1",
   "type": "module",
   "scripts": {
     "dev": "vite --port 5199 --host",