- Move import page, tabs, workflow state, and route tests into React-owned route slices
- Preserve shell gating, staging queries, album matching, singles matching, auto-import, and queue behavior
- Add migration plan snapshot so cleanup/refinement can build on a stable baseline
Keep WebUI migration plans next to the frontend code so route work
has one predictable home.
Standardize the set around one page migration overview plus
per-route migration plan docs for future tasks.