feat: JKKP 6/7 PDF generation via pdf-lib, download from incident detail

Also excludes node_modules.nosync from vitest test discovery to fix pre-existing bleed.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FFDuBhMKvoWjrWT3ZnGmmr

package.json

@@ -15,6 +15,7 @@
     "@supabase/ssr": "^0.12.0",
     "@supabase/supabase-js": "^2.110.2",
     "next": "^15.5.20",
+    "pdf-lib": "^1.17.1",
     "react": "^19.2.7",
     "react-dom": "^19.2.7",
     "resend": "^6.17.2"