Build JS on CI host, copy dist into Docker image for faster arm64 builds; v1.0.5

Removes the build stage from Dockerfile so npm install/build no longer run under
QEMU emulation — only the lightweight runtime stage runs per-platform, making
arm64 images build reliably.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "siteforge",
-  "version": "1.0.4",
+  "version": "1.0.5",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "siteforge",
-      "version": "1.0.4",
+      "version": "1.0.5",
       "dependencies": {
         "@dnd-kit/core": "^6.3.1",
         "@dnd-kit/sortable": "^10.0.0",