Cookie Consent Audit & Fix

Users are being re-prompted to accept cookies after every site release. The current implementation stores consent in localStorage via a custom composable that has several reliability issues — no shared state, fragile storage, and no fallback mechanism.

Consent decisions persist reliably across deploys, browser restarts, and normal browsing conditions. The banner only re-appears when consent genuinely expires (1 year) or the user clears it manually.

• In: useConsent.ts, CookieConsentBanner.vue, useGTM.ts, gtm.client.ts, nuxt.config.ts
• Out: Third-party consent platforms (OneTrust, Cookiebot), GDPR granular category UI (future cycle)

• Rewrote useConsent.ts: replaced localStorage + ref() with useCookie() + useState()
• Cookie qpoint-consent now persists consent (survives deploys, readable server-side)
• useState() ensures all components share a single reactive state
• Added one-time migration: reads old qpoint-cookie-consent from localStorage, writes to cookie, deletes old key
• Simplified CookieConsentBanner.vue: removed redundant local ref and watchEffect
• Updated DevDebugger.vue to read from cookie instead of localStorage
• Removed stale consentGiven reference from useGTM.ts