feat: pure Dioxus attack chain visualization, PDF report redesign, and orchestrator data fixes

- Replace vis-network JS graph with pure RSX attack chain component
  featuring KPI header, phase rail, expandable accordion with tool
  category chips, risk scores, and findings pills
- Redesign pentest report as professional PDF-first document with
  cover page, table of contents, severity bar chart, phased attack
  chain timeline, and print-friendly light theme
- Fix orchestrator to populate findings_produced, risk_score, and
  llm_reasoning on attack chain nodes
- Capture LLM reasoning text alongside tool calls in LlmResponse enum
- Add session-level KPI fallback for older pentest data
- Remove attack-chain-viz.js and prototype files
- Add encrypted ZIP report export endpoint with password protection

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

docs/.vitepress/config.mts

@@ -30,6 +30,7 @@ export default defineConfig({
         items: [
           { text: 'Dashboard Overview', link: '/features/overview' },
           { text: 'DAST Scanning', link: '/features/dast' },
+          { text: 'AI Pentest', link: '/features/pentest' },
           { text: 'AI Chat', link: '/features/ai-chat' },
           { text: 'Code Knowledge Graph', link: '/features/graph' },
           { text: 'MCP Integration', link: '/features/mcp-server' },