Editorial/Judicial design system — Phase B visual overhaul

- New design-system.css: CSS variables for Navy/Cream/Gold palette,
  Frank Ruhl Libre (display) + Assistant (body) typography via Google Fonts,
  spacing/shadow/motion tokens, RTL-safe utilities
- All body paragraphs justify to both sides (text-align: justify, inter-word)
- Existing inline <style> migrated from hardcoded #e94560/#1a1a2e/#27ae60 to
  CSS variables
- Header: deep navy with gold accent rule under, display-font brand mark,
  active nav link marked with gold underline
- Buttons: navy primary, gold-wash focus rings, elevation on hover
- Case cards: gold right-border, hairline top glow on hover, display font
  on case number
- Home dashboard: new hero with eyebrow/title/subtitle, 4 KPI cards with
  gold-rule side marker, loadKPIs() fetches case count, corpus size,
  pattern count, processing queue
- Style report: larger hero h1, ornamental pull-quote headline with
  drop-cap open quote, gold divider under section titles
- Toast, status bar, form inputs: navy/gold palette, serif italics for
  subtitles and empty states

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

web/app.py

@@ -69,6 +69,11 @@ async def index():
     return FileResponse(STATIC_DIR / "index.html")
 
 
+@app.get("/design-system.css")
+async def design_system_css():
+    return FileResponse(STATIC_DIR / "design-system.css", media_type="text/css")
+
+
 @app.post("/api/upload")
 async def upload_file(file: UploadFile = File(...)):
     """Upload a file to the temporary uploads directory."""