Add Chain Insights case knowledge exports

[aph5nt]

Summary

• Add shared case export service for Obsidian, LLMWiki, JSON Canvas, graph JSON, and agent prompt bundles.
• Add cia case export and MCP case_export adapters over the same service.
• Document the workflow, update shipped skills, bump package to 0.3.3, and refresh dist.

Test Plan

• npm test -- tests/case-export-schema.test.ts tests/case-export-redaction.test.ts tests/case-export.test.ts tests/case-export-canvas.test.ts tests/cli.test.ts tests/mcp-proxy.test.ts
• npm run typecheck
• npm run build
• npm test
• npm run release:check
• clean-workspace dogfood: init, case open, evidence add/verify, case export, JSON parse Graph.canvas/manifest/graph