TrueGrowth/openspec/changes/refactor-workflow-shell/design.md

Context

Video analyzer, MV creator, and music analyzer each own their page routing and domain-specific task interpretation, but they duplicate workflow shell lifecycle code.

Decisions

• Keep domain sync logic in each workflow's existing task-sync.ts.
• Share only the thin shell concerns:
  • step rendering and disabled step behavior
  • step/history/starred navigation shell rendering
  • page and history/starred navigation actions
  • record list/current record/starred UI state
  • completed task scan, subscription, in-flight de-dupe, and unmount cleanup
• Keep storage keys, record schemas, task metadata, provider routing, media execution, and service worker behavior unchanged.

Failure Modes

• Task sync handlers may throw; the shared hook logs the failure and releases the in-flight task id.
• Task sync may finish after unmount; the shared hook drops late results.
• Record loading may fail or return bad data; the shared record hook falls back to an empty list without changing storage.