feat: Snippets "The Lab" — category filters, search, language badges, code preview, modal keyboard nav (#72)

* fix: pass locale explicitly to Hero and force-dynamic on locale-sensitive API routes

- Hero.tsx: pass locale prop directly to getTranslations instead of
  relying on setRequestLocale async storage, which can be lost during
  Next.js RSC streaming
- book-reviews route: replace revalidate=300 with force-dynamic to
  prevent cached English responses being served to German locale requests
- content/page route: add runtime=nodejs and force-dynamic (was missing
  both, violating CLAUDE.md API route conventions)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix: scroll to top on locale switch and remove dashes from hero text

- HeaderClient: track locale prop changes with useRef and call
  window.scrollTo on switch to reliably reset scroll position
- messages/en.json + de.json: replace em dash with comma and remove
  hyphens from Self-Hoster/Full-Stack in hero description

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* Initial plan

* feat: improve Snippets/The Lab UI with category filters, search, language badges and code preview

Agent-Logs-Url: https://github.com/denshooter/portfolio/sessions/4a562022-cad7-4b4f-8bc4-1be022ecbf1e

Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

---------

Co-authored-by: denshooter <dennis@konkol.net>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

messages/en.json

@@ -35,7 +35,7 @@
         "f2": "Docker Swarm & CI/CD",
         "f3": "Self-Hosted Infrastructure"
       },
-      "description": "I'm Dennis – a student from Germany and a passionate self-hoster. I build full-stack applications and love the challenge of managing the infrastructure they run on.",
+      "description": "I'm Dennis, a student from Germany and a passionate selfhoster. I build fullstack applications and love the challenge of managing the infrastructure they run on.",
       "ctaWork": "View Projects",
       "ctaContact": "Get in touch"
     },