Task 041: Report Navigation and Source Link Improvements

Status: DONE

Motivation

Human directive: "分析レポートページの分かりやすさを適宜確認して改善すること。例えば今出典のリンクが無く出典元にジャンプできない。別レポートや別セクションにもジャンプ可能であってほしい。"

Current issues:

1. Source citations lack clickable links — SourceCitation type has a url field but it may not be rendered as a clickable hyperlink in all contexts
2. No inter-report navigation — Episode pages don't link to each other or to the summary
3. No intra-page navigation — No table of contents or section anchors for jumping within a long report

Scope

1. Ensure all SourceCitation URLs are rendered as clickable <a> tags
2. Add inter-report navigation bar (episode ↔ episode, episode ↔ summary)
3. Add section anchors (id attributes) on transfer/exploration headings
4. Add table of contents at the top of each episode report
5. Ensure cross-episode report also has working navigation
6. Update tests for new template output

Depends on

• Report pipeline (Task 005, 010, 012)
• Templates (templates.ts)
• All episode reports (ep01-ep05)