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

cspell.json

@@ -0,0 +1,17 @@
+{
+  "version": "0.2",
+  "language": "en",
+  "files": ["content/**/*.md"],
+  "dictionaries": ["project-words"],
+  "dictionaryDefinitions": [
+    { "name": "project-words", "path": "./.cspell/words.txt", "addWords": true }
+  ],
+  "ignoreRegExpList": [
+    "/^\\s*```[\\s\\S]*?^\\s*```/gm",
+    "/`[^`\\n]+`/g",
+    "/\\$\\$[\\s\\S]*?\\$\\$/g",
+    "/\\$[^$\\n]+\\$/g",
+    "/\\b[0-9a-f]{16,}\\b/gi",
+    "/\\w+\\{[^}\\n]*\\}/g"
+  ]
+}