feat: Replace Medium Blog Integration with Ghost CMS

[CeylonT]

This PR replaces the existing Medium integration with a native Ghost CMS integration to improve SEO, ownership, and editorial control. Blog content is now fetched via the Ghost Content API and rendered using Nuxt's static site generation.

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✨ Changes

• Added a reusable Ghost client composable
• Updated API endpoints to fetch content from Ghost instead of Medium
• Implemented dynamic routing for blog posts using /blog/[slug]
• Updated UI components to align with Ghost's content structure
• Remove unnecessary cache
• Update readme

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🧪 Todo – Testing

• Verify behavior when duplicate titles exist (e.g., slug collision) (blog URLs are generated from titles)

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🧹 Todo – Handling & Cleanup

• Add fallback image handling for posts without a feature image
• Remove deprecated variables/code (e.g., blogFeedUrl)
• Add Ghost blog URL to socialNetworks in defineAppConfig then update footer

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🧪 Todo – Self-hosted Ghost PoC

• Add Docker Compose setup for local Ghost CMS (docs)
• Test and validate integration with self-hosted Ghost instance