Task 186: Episode Report MDX Migration (EP01 Pilot)

Status: DONE

Description

Migrate episode reports from JSON to MDX-like format for improved reviewability. JSON with embedded HTML/markdown is hard to review — MDX allows reviewers to focus on the analysis text. Start with EP01 as a pilot.

Summary reports were migrated in Task 175. Episode reports (5125 lines of JSON across 5 episodes) remain in the old format. The goal is to move the prose content (transfer explanations, verdict summaries, exploration summaries) to readable markdown while keeping structured data (parameters, sources, numeric values) as JSON directives.

Design (per Codex consultation)

Hybrid approach (Option C): Separate episode MDX parser/assembler.

File format: ep01.md

---
episode: 1
title: "SOLAR LINE Part 1 — 火星からガニメデへ"
summary: "きりたんが小型貨物船..."
---

[{ "provider": "niconico", "id": "sm45280425", ... }, ...]

[{ "id": "ep01-quote-01", "speaker": "ケイ", ... }, ...]

## ep01-transfer-01

ホーマン遷移基準値: 火星軌道 → 木星軌道（最小エネルギー）

{ "id": "ep01-transfer-01", "timestamp": "該当なし（参考計算）", ... }

古典的ホーマン遷移には合計約10.15 km/sのΔVが必要だが...
(explanation prose in natural markdown)

## ep01-transfer-02

(next transfer...)

Key principles:

1. Separate parser: episode-mdx-parser.ts, NOT extending mdx-parser.ts
2. Sections keyed by transfer ID: ## ep01-transfer-XX headings map to transfers
3. Explanation as section markdown: Section text below the transfer: directive becomes TransferAnalysis.explanation
4. Frontmatter scalar only: Current YAML parser handles scalars; arrays go in directives
5. Output: Parser produces EpisodeReport objects — existing renderEpisode() unchanged
6. Exploration sections: ### ep01-exp-XX within transfer sections
7. Report-level arrays: diagrams:, timeseries:, detail-pages: as top-level directives (before first ## or in a dedicated section)

Build pipeline changes:

• discoverEpisodes() in build.ts: also look for ep\d+\.md files
• Conflict check: throw if both .json and .md exist for same episode

Scope (this task)

1. Write episode MDX parser with TDD
2. Update build.ts to discover .md episode files
3. Convert ep01.json → ep01.md
4. Verify all existing tests still pass (including data validation)
5. Delete ep01.json after successful migration

Dependencies

• MDX parser infrastructure (mdx-parser.ts, Task 127/175)
• EP01 report data (ep01.json)

Future (separate tasks)

• EP02-EP05 migration
• Exploration directive support
• detailPages directive support