chore: add tailwindcss dependency and remove .npmrc from workflow rules

Sync with upstream template: tailwindcss ^4.2.2 added as explicit dep,
.npmrc removed from apply rules since the file no longer exists.
Also add catch-all rule for unlisted upstream files.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Alexandre Nédélec

.github/workflows/template-sync.md

@@ -68,7 +68,6 @@ apply or adapt (see rules below), fetch its current content from `nuxt-ui-templa
 - `eslint.config.mjs`
 - `tsconfig.json`
 - `pnpm-workspace.yaml`
-- `.npmrc` — apply changes (or deletion) as-is
 - `package.json` — apply only updates to **shared** dependencies (nuxt, @nuxt/ui, @nuxt/content,
   @nuxt/image, @nuxt/fonts, @nuxt/icon, typescript, vue, etc.). Do NOT remove packages that
   exist in this repo but not the template (e.g. @nuxtjs/seo, gsap, @vueuse/nuxt, and others).

package.json

@@ -32,6 +32,7 @@
     "nuxt": "^4.2.2",
     "posthog-js": "^1.345.2",
     "submitjson": "^0.14.0",
+    "tailwindcss": "^4.2.2",
     "ufo": "^1.6.3",
     "zod": "^4.3.6"
   },