Update dependencies and website content (#17)

* Update dependencies and website content

- Update all dependencies to latest versions (browser-sync 3.0.4, @fancyapps/ui 6.0.32, sass 1.93.2, sass-loader 16.0.5, browser-sync-webpack-plugin 2.4.0)
- Fix @fancyapps/ui CSS import path for v6 compatibility
- Change codec link from papi.fluffylabs.dev to codec.fluffylabs.dev
- Replace trie visualiser with state viewer project
- Update state viewer description and links to state.fluffylabs.dev and GitHub repo
- Remove typeberry stealth mode and add repository link to github.com/fluffylabs/typeberry

Co-Authored-By: Tomek Drwięga <tomusdrw+github@gmail.com>

* Update copyright year to 2025 in footer

Co-Authored-By: Tomek Drwięga <tomusdrw+github@gmail.com>

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Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Tomek Drwięga <tomusdrw+github@gmail.com>

Author: devin-ai-integration[bot]