Immutable public and global content management (#5390)

* Use custom init script instead of postinstall

* Revert changes to start scripts in src\electron

* Add global data to content manager

* Add migration for public overrides and user.css location update

* Update npm publish workflow to use 'omit=dev' flag in npm ci commands

* Rename user.css readme file

* Fix indentation in userCssMiddleware function

* Add directory creation for content target

* Restore template compile location

* Move stylesheet up in index.json

* Use path.resolve for user.css file path in userCssMiddleware

* Correct capitalization in "Not Found" error page title and heading

* Remove init run from startup scripts

* Simplify user CSS file path resolution

* Update userCssMiddleware comment

.github/workflows/npm-publish.yml

@@ -19,7 +19,7 @@ jobs:
       - uses: actions/setup-node@3235b876344d2a9aa001b8d1453c930bba69e610 # v3
         with:
           node-version: 24
-      - run: npm ci
+      - run: npm ci --omit=dev --ignore-scripts
 
   publish-npm:
     needs: build
@@ -30,5 +30,5 @@ jobs:
         with:
           node-version: 24
           registry-url: https://registry.npmjs.org/
-      - run: npm ci
+      - run: npm ci --omit=dev --ignore-scripts
       - run: npm publish