feat: allow hidden tags, either permanent or when there are no unread messages

stores/__tests__/settings-store-keywords.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect, beforeEach } from 'vitest';
-import { useSettingsStore, DEFAULT_KEYWORDS, KEYWORD_PALETTE } from '../settings-store';
+import { useSettingsStore, DEFAULT_KEYWORDS, KEYWORD_PALETTE, getKeywordVisibility } from '../settings-store';
 import type { KeywordDefinition } from '../settings-store';
 
 describe('settings-store keywords', () => {
@@ -157,6 +157,17 @@ describe('settings-store keywords', () => {
     });
   });
 
+  describe('getKeywordVisibility', () => {
+    it('treats a tag stored before visibility was configurable as always shown', () => {
+      expect(getKeywordVisibility({ id: 'red', label: 'Red', color: 'red' })).toBe('show');
+    });
+
+    it('returns the stored choice when there is one', () => {
+      expect(getKeywordVisibility({ id: 'red', label: 'Red', color: 'red', visibility: 'unread' })).toBe('unread');
+      expect(getKeywordVisibility({ id: 'red', label: 'Red', color: 'red', visibility: 'hide' })).toBe('hide');
+    });
+  });
+
   describe('nestedTags', () => {
     it('is off by default', () => {
       useSettingsStore.getState().resetToDefaults();

stores/settings-store.ts

@@ -101,10 +101,19 @@ export const ALL_DEBUG_CATEGORIES: { id: DebugCategory; labelKey: string }[] = [
   { id: 'contacts', labelKey: 'contacts' },
 ];
 
+/** Whether a tag shows in the sidebar always, only when it has unread mail, or never. */
+export type KeywordVisibility = 'show' | 'hide' | 'unread';
+
 export interface KeywordDefinition {
   id: string;     // Used as JMAP keyword suffix: $label:<id>
   label: string;  // Display name
   color: string;  // Key from KEYWORD_PALETTE
+  visibility?: KeywordVisibility; // Absent on tags stored before this was configurable
+}
+
+/** Resolves the sidebar visibility of a tag, defaulting to always shown. */
+export function getKeywordVisibility(keyword: KeywordDefinition): KeywordVisibility {
+  return keyword.visibility ?? 'show';
 }
 
 export interface SidebarApp {