v2: light editorial redesign, bilingual (EN-first), preview, front matter, PWA

Design (design-taste-frontend + ui-ux-design-pro + impeccable):
- Warm, flat, light editorial theme (OKLCH), Geist + Geist Mono, single vermilion accent
- Dark mode toggle, persisted; respects prefers-color-scheme
- Prominent focus rings, tactile states, reduced-motion

Features (GitHub-ready):
- i18n EN/DE, English default, persisted
- Live split preview (marked + DOMPurify, sanitized)
- Optional YAML front matter (title/date/source/tags), rendered as metadata block
- Conversion options: links as text, strip images, bullet marker, heading style
- Filename patterns (title+date / date+time), auto/custom indicator
- Drag & drop .html/.md/.txt, reading time
- Installable PWA + service worker (offline), README (EN) + MIT LICENSE

Fix: switch inputs were covered by decorative spans (pointer-events).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

manifest.webmanifest

@@ -0,0 +1,13 @@
+{
+  "name": "clip2md — Paste to Markdown",
+  "short_name": "clip2md",
+  "description": "Paste rich text or a web page and save it as clean Markdown in one keystroke. Client-side, private, offline-capable.",
+  "start_url": ".",
+  "scope": ".",
+  "display": "standalone",
+  "background_color": "#faf7f2",
+  "theme_color": "#faf7f2",
+  "icons": [
+    { "src": "icon.svg", "sizes": "any", "type": "image/svg+xml", "purpose": "any maskable" }
+  ]
+}