# TASK 37 — Defaults vs current layout split

**Status:** ☐ Queued (2026-09-20)

## Idea (creator directive 2026-09-20)

The app establishes a DB of static, branded layout objects as its defaults. Today the DB is BOTH the
defaults and the live workspace: `LayoutStore.Save` deletes and reinserts the whole layout on every
save, so "your last edit" and "the defaults" occupy the same rows. The recurring "reorder doesn't
persist" bug was a symptom of that conflation.

Store TWO data sets:

- **`default`** — the established DB (branded factory scenes/layers), never mutated by user edits.
- **`current`** — whatever the user currently has, stamped with the build-id.

Load rule: honor `current` **iff** its build-id equals the running build's id (`BuildStamp.Id`),
otherwise load `default`. Bonus: one-click "revert to defaults" = drop `current`.

Two implementations were floated (config file vs second rows in the same DB); nothing decided — both
are OPS acceptable to the creator. The proposed conceptual shape:

```
scene[0-4].layerList.[default | current].elementList
```

## Notes / facts established while investigating

- `SceneCatalog` only defines the five canonical scene **names**; the actual default element set
  exists only as whatever the DB holds at first migration. There is no standalone in-code factory
  element set — "defaults" at migration time = a snapshot of today's DB.
- SortOrder is a DB column only (not on models); `Source` and `WebcamSceneConfig` were stamped with
  independent per-type sort counters and load appended all sources before all configs. That
  cross-table order bug is ALREADY FIXED (2026-09-20, unified z-space, see commit) — TASK 37 is the
  defaults/current data split on top of it.
- `MainViewModel.LoadLayout` (MainViewModel.cs:348) seeds `SceneCatalog.All` when `Scenes.Count == 0`
  and SaveLayoutNow deletes/reinserts everything (LayoutStore.Save.cs). Startup path:
  `%APPDATA%\ytLlive\ytLlive.db` (MainViewModel.cs:332), `LayoutPathOverride` test seam.

## Acceptance

- A saved `current` layout with a matching build-id restores on start.
- A `current` stamped by a different (older/newer) build-id falls back to `default`.
- Revert-to-default restores `default` for one scene or all.

## Cross-references

- `ai.md` — persistence architecture; `MyMistakes.md` — prior reorder persistence failures.