Replace Astro/Strapi site with Next.js static export

- Fresh structure: Next.js App Router + Tailwind v4 at the repo root, exported
  as static files (output: export) and served by static-web-server
- Remove the Strapi CMS, Astro app, Pagefind search, comments, old scripts,
  Lighthouse config and compose files; content in content/ is now plain
  markdown with YAML frontmatter
- Pages: About, Writing, Reading (3D bookshelf) and Portfolio, styled after
  adammaj.com
- SEO: metadata and canonicals, JSON-LD, generated OG images, sitemap, robots,
  RSS and JSON feeds, llms.txt
- Umami via PUBLIC_UMAMI_SCRIPT_URL / PUBLIC_UMAMI_WEBSITE_ID (build args)
- Dockerfile builds the export and serves it with sws.toml (security headers,
  clean URLs, .well-known, OG image content type, immutable asset caching)
- Prettier and cspell for content with a husky/lint-staged pre-commit hook
- Old redirect list dropped to start from a clean slate

.gitignore

@@ -1,6 +1,41 @@
-/public
-node_modules
-manimations/*.*
-/zola
-/zola-v*.tar.gz
-/artifacts
+# See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
+
+# dependencies
+/node_modules
+/.pnp
+.pnp.*
+.yarn/*
+!.yarn/patches
+!.yarn/plugins
+!.yarn/releases
+!.yarn/versions
+
+# testing
+/coverage
+
+# next.js
+/.next/
+/out/
+
+# production
+/build
+
+# misc
+.DS_Store
+*.pem
+
+# debug
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+.pnpm-debug.log*
+
+# env files (can opt-in for committing if needed)
+.env*
+
+# vercel
+.vercel
+
+# typescript
+*.tsbuildinfo
+next-env.d.ts