M5 §3/6: npm run dev fails until @nextcloud/browserslist-config is installed

From beta feedback by @yard-mschwartz (2026-08-10 batch).

I needed to run npm install --save-dev @nextcloud/browserslist-config before npm run dev was successful.

PHP Track > M5 Frontend Toolchain > Section 3/6, Exercise.

The module's package.json (or the browserslist config it ships) references @nextcloud/browserslist-config without listing it as a devDependency, so a clean install leaves the reader unable to run the very command the exercise is built around. Add it to the dependency list the module tells readers to install, rather than documenting the extra npm install as a workaround.

Fix this together with the still-open @nextcloud/webpack-vue-config item from Marc's first feedback batch (bump ^6.0.0 → ^7.0.0 so the EBADENGINE warning on Node 24 goes away). Both are M5 toolchain dependency gaps hitting the same reader at the same point, and both want a real npm install + npm run dev run to verify — so it's one pass, not two.

Start with the module's package.json and any browserslist configuration it ships, then check how the exercise's dependencies are installed. Add the missing dependency and address the linked @nextcloud/webpack-vue-config version update, then run npm install and npm run dev. Done means a clean install lets the exercise command run without the reported dependency gap or Node 24 warning.