refactor(settings): move Default Highlight Visibility to Reading & Display

- Move setting from Startup Preferences to Reading & Display section
- Position above preview so changes are immediately visible
- Update preview to respect defaultHighlightVisibility settings
- Each highlight level (mine/friends/nostrverse) now toggles in preview

src/components/Settings/ReadingDisplaySettings.tsx

@@ -1,5 +1,6 @@
 import React from 'react'
-import { faHighlighter, faUnderline } from '@fortawesome/free-solid-svg-icons'
+import { FontAwesomeIcon } from '@fortawesome/react-fontawesome'
+import { faHighlighter, faUnderline, faNetworkWired, faUserGroup, faUser } from '@fortawesome/free-solid-svg-icons'
 import { UserSettings } from '../../services/settingsService'
 import IconButton from '../IconButton'
 import ColorPicker from '../ColorPicker'
@@ -107,6 +108,39 @@ const ReadingDisplaySettings: React.FC<ReadingDisplaySettingsProps> = ({ setting
         </div>
       </div>
 
+      <div className="setting-group setting-inline">
+        <label>Default Highlight Visibility</label>
+        <div className="highlight-level-toggles">
+          <button
+            onClick={() => onUpdate({ defaultHighlightVisibilityNostrverse: !(settings.defaultHighlightVisibilityNostrverse !== false) })}
+            className={`level-toggle-btn ${(settings.defaultHighlightVisibilityNostrverse !== false) ? 'active' : ''}`}
+            title="Nostrverse highlights"
+            aria-label="Toggle nostrverse highlights by default"
+            style={{ color: (settings.defaultHighlightVisibilityNostrverse !== false) ? 'var(--highlight-color-nostrverse, #9333ea)' : undefined }}
+          >
+            <FontAwesomeIcon icon={faNetworkWired} />
+          </button>
+          <button
+            onClick={() => onUpdate({ defaultHighlightVisibilityFriends: !(settings.defaultHighlightVisibilityFriends !== false) })}
+            className={`level-toggle-btn ${(settings.defaultHighlightVisibilityFriends !== false) ? 'active' : ''}`}
+            title="Friends highlights"
+            aria-label="Toggle friends highlights by default"
+            style={{ color: (settings.defaultHighlightVisibilityFriends !== false) ? 'var(--highlight-color-friends, #f97316)' : undefined }}
+          >
+            <FontAwesomeIcon icon={faUserGroup} />
+          </button>
+          <button
+            onClick={() => onUpdate({ defaultHighlightVisibilityMine: !(settings.defaultHighlightVisibilityMine !== false) })}
+            className={`level-toggle-btn ${(settings.defaultHighlightVisibilityMine !== false) ? 'active' : ''}`}
+            title="My highlights"
+            aria-label="Toggle my highlights by default"
+            style={{ color: (settings.defaultHighlightVisibilityMine !== false) ? 'var(--highlight-color-mine, #eab308)' : undefined }}
+          >
+            <FontAwesomeIcon icon={faUser} />
+          </button>
+        </div>
+      </div>
+
       <div className="setting-preview">
         <div className="preview-label">Preview</div>
         <div 
@@ -118,9 +152,9 @@ const ReadingDisplaySettings: React.FC<ReadingDisplaySettingsProps> = ({ setting
           } as React.CSSProperties}
         >
           <h3>The Quick Brown Fox</h3>
-          <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. <span className={settings.showHighlights !== false ? `content-highlight-${settings.highlightStyle || 'marker'} level-mine` : ""}>Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.</span> Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
-          <p>Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. <span className={settings.showHighlights !== false ? `content-highlight-${settings.highlightStyle || 'marker'} level-friends` : ""}>Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</span> Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium.</p>
-          <p>Totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo. <span className={settings.showHighlights !== false ? `content-highlight-${settings.highlightStyle || 'marker'} level-nostrverse` : ""}>Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt.</span> Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit.</p>
+          <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. <span className={settings.showHighlights !== false && settings.defaultHighlightVisibilityMine !== false ? `content-highlight-${settings.highlightStyle || 'marker'} level-mine` : ""}>Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.</span> Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
+          <p>Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. <span className={settings.showHighlights !== false && settings.defaultHighlightVisibilityFriends !== false ? `content-highlight-${settings.highlightStyle || 'marker'} level-friends` : ""}>Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</span> Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium.</p>
+          <p>Totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo. <span className={settings.showHighlights !== false && settings.defaultHighlightVisibilityNostrverse !== false ? `content-highlight-${settings.highlightStyle || 'marker'} level-nostrverse` : ""}>Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt.</span> Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit.</p>
           <p>Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo. Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt.</p>
         </div>
       </div>

src/components/Settings/StartupPreferencesSettings.tsx

@@ -1,6 +1,4 @@
 import React from 'react'
-import { FontAwesomeIcon } from '@fortawesome/react-fontawesome'
-import { faNetworkWired, faUserGroup, faUser } from '@fortawesome/free-solid-svg-icons'
 import { UserSettings } from '../../services/settingsService'
 
 interface StartupPreferencesSettingsProps {
@@ -38,39 +36,6 @@ const StartupPreferencesSettings: React.FC<StartupPreferencesSettingsProps> = ({
           <span>Start with highlights panel collapsed</span>
         </label>
       </div>
-
-      <div className="setting-group setting-inline">
-        <label>Default Highlight Visibility</label>
-        <div className="highlight-level-toggles">
-          <button
-            onClick={() => onUpdate({ defaultHighlightVisibilityNostrverse: !(settings.defaultHighlightVisibilityNostrverse !== false) })}
-            className={`level-toggle-btn ${(settings.defaultHighlightVisibilityNostrverse !== false) ? 'active' : ''}`}
-            title="Nostrverse highlights"
-            aria-label="Toggle nostrverse highlights by default"
-            style={{ color: (settings.defaultHighlightVisibilityNostrverse !== false) ? 'var(--highlight-color-nostrverse, #9333ea)' : undefined }}
-          >
-            <FontAwesomeIcon icon={faNetworkWired} />
-          </button>
-          <button
-            onClick={() => onUpdate({ defaultHighlightVisibilityFriends: !(settings.defaultHighlightVisibilityFriends !== false) })}
-            className={`level-toggle-btn ${(settings.defaultHighlightVisibilityFriends !== false) ? 'active' : ''}`}
-            title="Friends highlights"
-            aria-label="Toggle friends highlights by default"
-            style={{ color: (settings.defaultHighlightVisibilityFriends !== false) ? 'var(--highlight-color-friends, #f97316)' : undefined }}
-          >
-            <FontAwesomeIcon icon={faUserGroup} />
-          </button>
-          <button
-            onClick={() => onUpdate({ defaultHighlightVisibilityMine: !(settings.defaultHighlightVisibilityMine !== false) })}
-            className={`level-toggle-btn ${(settings.defaultHighlightVisibilityMine !== false) ? 'active' : ''}`}
-            title="My highlights"
-            aria-label="Toggle my highlights by default"
-            style={{ color: (settings.defaultHighlightVisibilityMine !== false) ? 'var(--highlight-color-mine, #eab308)' : undefined }}
-          >
-            <FontAwesomeIcon icon={faUser} />
-          </button>
-        </div>
-      </div>
     </div>
   )
 }