`useHead` does not resolve reactive input on the client

[Carpediem94]

🐛 The bug

The module's useHead replacement (src/runtime/composables/head.ts) never resolves reactive input. All of its activeHead.push() / patch() sites hand the raw object to unhead, while @unhead/vue's own clientUseHead runs walkResolver(input, VueResolver) inside a watchEffect.

This only bites on the client: @unhead/vue/server creates the head with propResolvers: [VueResolver], so refs resolve inside unhead during SSR. The client head has no prop resolver, so resolution exists only in the composable this module replaces.

Two consequences:

1. Crash — a ref on innerHTML/textContent of a style/script reaches unhead's normalizeProps, which JSON-stringifies object values:

   TypeError: Converting circular structure to JSON
       --> starting at object with constructor 'ComputedRefImpl'
       |     property 'dep' -> object with constructor 'Dep'
       --- property 'computed' closes the circle
       at JSON.stringify (<anonymous>)
       at normalizeProps (unhead.js:148:28)
       at normalizeTag (unhead.js:175:15)
       at normalizeEntryToTags (unhead.js:209:56)
       at resolveTags (unhead.js:362:16)
       at _renderDOMHead (unhead.js:183:21)
   

   It is thrown inside the debounced _renderDOMHead, so the whole head render is abandoned: the tag never lands in the DOM, and it can abort router start.

2. Silent, for every other prop: the ref object is used instead of its .value, and since there is no watchEffect, the tag never updates when the ref changes. Client-side reactive head does not work, though unhead v3 documents it as supported.

@nuxt/ui triggers case 1 out of the box: its colors plugin calls useHead({ style: [{ innerHTML: root, id: 'nuxt-ui-colors' }] }) where root is a computed. Any @nuxtjs/ionic + @nuxt/ui app loses its theme colors style. @nuxtjs/i18n's useLocaleHead() and @nuxtjs/seo hit case 2.

🛠️ To reproduce

https://github.com/Carpediem94/nuxt-ionic-head-repro

🌈 Expected behaviour

Reactive input resolved before being pushed to unhead, and kept in sync as it changes, matching the behaviour of @unhead/vue's useHead.

ℹ️ Additional context

@nuxtjs/ionic 1.0.2, nuxt 4.5.2, @unhead/vue 3.3.1, @nuxt/ui 4.10.0.

Same error class as unjs/unhead#869, but that fix only covered the SSR streaming serializer.