Workspace transfer: custom themes ride the export/import envelope

docs/chart-theming-scope.md

@@ -142,7 +142,7 @@ ships, it is an explicit per-font user action, never automatic.
    (spec §03G): bake the active theme into `spec.config` (existing keys win,
    render-identical), or lift `spec.config` out to the clipboard (copy before remove —
    a failed copy aborts).
-4. **Custom named themes** ✅ (2026-06-12, except export/import) — IndexedDB entity
+4. **Custom named themes** ✅ (2026-06-12) — IndexedDB entity
    `{ id, name, config }` (`core/custom-theme.ts`, themes store @ DB v2) + the **Theme
    Builder** modal: theme list, JSON config editor, a font control that populates one
    family across every font slot (`applyFontToConfig`), and a live multi-chart gallery
@@ -151,8 +151,9 @@ ships, it is an explicit per-font user action, never automatic.
    theme (house/preset/custom) or via the editor's **Extract Config to New Theme**
    action (spec §03G); appears in the selector as `custom:<id>` (the "Edit themes…"
    action row sits right after the customs, before the preset roster); deleting the
-   active one falls back to Astrolabe. **Remaining:** export/import as JSON alongside
-   the library (touches the §08 envelope + import-normalize atomicity).
+   active one falls back to Astrolabe. Custom themes travel in the §08 workspace
+   export/import envelope (additive `themes` array, name auto-suffix on clash, ids
+   reassigned by the store, rolled back with datasets on a failed import).
 5. **Shipped font roster** — fontsource packages, `@font-face` registration, selector
    metadata (which themes/fonts pair), `document.fonts.load` gate in the render path,
    precache strategy above. Roster finalized via visual specimen.
@@ -166,6 +167,16 @@ it without a second mechanism).
 
 ## 5. Status log
 
+- **2026-06-12 (slice 4 close-out)** — **custom themes in the §08 envelope.** The
+  workspace export now writes a `themes` array (additive — no format bump; importers
+  treat it as optional, so pre-theme envelopes stay valid). Import normalizes each
+  record (`normalizeCustomTheme`), auto-suffixes name clashes via the generalized
+  `dedupeIncomingNames` (the dataset dedupe, now shared), reassigns ids through
+  `CustomThemeStore.addThemes` (selection untouched), and rolls themes back together
+  with datasets when the atomic snippet write fails. Toast counts gain a theme
+  clause. Spec §08 updated ("Dataset conflicts" → "Name conflicts"). Slice 4 is now
+  fully done; next is slice 5 (shipped font roster).
+
 - **2026-06-12 (slice 4)** — **custom named themes + Theme Builder shipped.**
   `CustomTheme` entity through the full stack (core → theme-store @ DB v2 →
   CustomThemeStore → theme-persistence → startup hydrate); selection model extended to