Add distributed settings and workspace import/export (M5)

src/app/modals/modal-registry.ts

@@ -10,8 +10,10 @@
  * single shell-level Save/Cancel doesn't fit). The registry therefore omits
  * `hasError`/`getError` (validity is the modal's own concern) and keeps only
  * `getState` for unsaved-change detection on close. The registry is a partial
- * map: modals land milestone by milestone (settings/about/donate → M5/M6,
- * chartBuilder → M4), so only the implemented ones are registered here.
+ * map: modals land milestone by milestone (about/donate → M6, chartBuilder → M4),
+ * so only the implemented ones are registered here. Settings is deliberately NOT
+ * a modal — preferences are distributed to per-pane disclosure popovers (spec §07;
+ * see components/SettingsPopover).
  */
 
 import type { ComponentType } from 'react';

src/app/modals/types.ts

@@ -9,11 +9,12 @@
 
 export type ModalName =
   | 'datasets' // Datasets manager (list / detail / new-dataset form)
-  | 'settings' // Appearance, editor, performance, formatting prefs (M5)
   | 'about' // About & Help (M6)
   | 'donate' // Donate (M6)
   | 'chartBuilder' // Visual no-JSON chart composition for a dataset (M4)
   | 'extract'; // Extract inline spec data into a new dataset (M3)
+// Settings is NOT a modal — preferences are distributed to per-pane disclosure
+// popovers (spec §07; see components/SettingsPopover).
 
 /** The active modal, or `null` when none is open (at most one at a time, §01C). */
 export type ActiveModal = ModalName | null;