Initial TrueGrowth source import

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

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+## 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.