[cmglezpdev]

What this changes

The flat store can persist and rediscover playlist records: PlaylistRecord, a StoredRecord union discriminated on kind, and FsStore scan/save/find support so list and purge see playlist directories.

Why

A playlist run needs its own record for resume, list grouping, and purge. Legacy video state.json files (no kind) keep parsing unchanged; savePlaylist never touches index.json.

How to verify

pnpm typecheck
pnpm vitest run src/domain/run src/adapters/store --exclude '**/.claude/**'

Note the behavioral shift in purge(): its code is untouched, but it now removes playlist directories because #scan() returns both record kinds.

Checklist

• pnpm typecheck and pnpm test pass
• Commits follow Conventional Commits

Scope

• Includes: playlist record + parser, stored-record union, store port additions, purge regression coverage.
• Excludes: orchestration, prompt, CLI.

Chain Context

Field	Value
Chain	playlist-support
Tracker PR	#40
Position	2 of 6
Base	feat/playlist-support-01-listing
Depends on	PR 1
Follow-up	PR 3a (packageName option)
Review budget	583 / 400

Chain Overview

main
 └── #40 tracker: feat/playlist-support
      └── 01 listing → 02 store → 03a packageName → 03b prompt → 04 orchestrator → 05 CLI
          (this PR: 📍 2)