feat(spaces): корзина, hard purge, transfer и полный backup

Soft-delete/restore/purge пространств, смена владельца, импорт JSON с spaces, proxy portal-users и polish Settings/ConfirmDialog.

Co-authored-by: Cursor <cursoragent@cursor.com>

packages/db/src/schema/index.ts

@@ -8,6 +8,8 @@ export const spaces = sqliteTable('spaces', {
   kind: text('kind').notNull().default('personal'),
   ownerUserId: text('ownerUserId'),
   createdAt: text('createdAt').notNull(),
+  /** Soft-delete (корзина); null = active */
+  deletedAt: text('deletedAt'),
 })
 
 export const spaceMembers = sqliteTable(