feat: plakat redesign phase 1 (tokens, fonts, poster hero, header)

- New design tokens: signal red, ink and paper as RGB channels; ink and paper
  swap roles in dark mode so every component inverts cleanly
- Fonts via next/font: Bricolage Grotesque (with wdth/opsz axes), Geist,
  Geist Mono; drop Inter and Playfair
- Poster hero: kicker, giant DK0 wordmark that reacts to pointer distance
  (weight and width through a damped spring, desktop only, off for reduced
  motion), claim as h1, intro with thesis countdown, marquee strip
- Header in poster style: transparent over the red hero, paper strip with
  ink rule when scrolled or on subpages; drawer menu restyled
- Remove wavy SVG separators, CSS shader gradient, background blobs and
  unused providers that caused the pink/purple bands between sections
- Drop the global p/span/div color override so colors inherit properly
- New hero texts in de/en, tests and i18n key check updated

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

messages/de.json

@@ -26,17 +26,12 @@
   },
   "home": {
     "hero": {
-      "badge": "Student & Self-Hoster",
-      "line1": "Building",
-      "line2": "Stuff.",
-      "features": {
-        "f1": "Next.js & Flutter",
-        "f2": "Docker Swarm & CI/CD",
-        "f3": "Self-Hosted Infrastruktur"
-      },
-      "description": "Ich bin Dennis Konkol, Informatik-Student und Webentwickler aus Osnabrück. Ich entwickle Fullstack-Apps mit Next.js und Flutter und betreibe meine eigene Infrastruktur mit Docker und CI/CD.",
-      "ctaWork": "Meine Projekte",
-      "ctaContact": "Kontakt"
+      "kicker": "Dennis Konkol — Osnabrück",
+      "claim": "Ich hoste mein halbes Leben selbst. Den Rest programmiere ich.",
+      "intro": "IT-Admin in Osnabrück und Masterstudent. Ab Februar 2027 kümmere ich mich hauptberuflich um Microsoft 365, bis dahin um meine Masterarbeit.",
+      "countdown": "{days, plural, one {Noch # Tag.} other {Noch # Tage.}}",
+      "ctaWork": "Projekte ansehen",
+      "ctaContact": "Schreib mir"
     },
     "about": {
       "title": "Hinter den Kulissen",