feat: P5-21 mention color, P5-22 font selector, P5-27 notification presets; update docs

- P5-21: Custom @mention highlight color picker in Settings → Appearance.
  CSS vars with luminance-computed text color; resets cleanly to theme default.
- P5-22: Font selector (System, Inter, JetBrains Mono, Fira Code) in
  Settings → Appearance. Fira Code added to Google Fonts preload.
- P5-27: Gaming/Work/Sleep preset buttons at top of Settings → Notifications.
  Each atomically applies a group of notification settings.
- AppearanceEffects component in App.tsx applies CSS vars on settings change.
- LOTUS_BUGS.md: mark presence + manifest icon bugs as resolved.
- LOTUS_TODO.md: mark P3-6, P5-21, P5-22, P5-27 as [x].
- LOTUS_FEATURES.md: document all four completed features.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

LOTUS_FEATURES.md

@@ -174,6 +174,30 @@ A warm orange overlay rendered over the entire UI to reduce blue light emission.
 
 ---
 
+## Font Selector (P5-22)
+
+Users can choose the UI font in **Settings → Appearance**:
+
+- **System Default** — `system-ui, -apple-system, sans-serif`
+- **Inter** — `'InterVariable', sans-serif` (current default)
+- **JetBrains Mono** — `'JetBrains Mono', monospace` (already loaded from Google Fonts)
+- **Fira Code** — `'Fira Code', monospace` (added to Google Fonts preload in `index.html`)
+
+Applied by overriding `--font-secondary` on `document.body` via `AppearanceEffects` in `App.tsx`. The TDS terminal mode font stack is unaffected.
+
+---
+
+## Custom @Mention Highlight Color (P5-21)
+
+Users can set a custom background color for `@mention` chips that highlight their own name, in **Settings → Appearance**.
+
+- Color picker (native `<input type="color">`) with a **Reset** button to revert to the theme default
+- Text color (black/white) auto-computed from the chosen background's luminance for readability
+- Applied via CSS custom properties `--mention-highlight-bg`, `--mention-highlight-text`, `--mention-highlight-border` set on `document.body`
+- `CustomHtml.css.ts` uses these as CSS `var()` fallbacks over the original folds `Success` token colors
+
+---
+
 ## Voice / Video Call Improvements
 
 ### Element Call Upgrade
@@ -589,6 +613,16 @@ A toggle in **Settings → Privacy** switches between sending `m.read` (public r
 
 A leading emoji in a room name is rendered at 1.15× size in the sidebar for visual hierarchy. An emoji picker button (😊) is added to all room name input fields, prepending the selected emoji to the room name.
 
+### Configurable Composer Toolbar (P3-6)
+
+Users can individually show or hide each composer toolbar button in **Settings → Editor → Composer Toolbar Buttons**:
+
+- Format Toggle, Emoji, Sticker, GIF, Location, Poll, Voice Message, Schedule Message
+- All default to **on** — no visible change for existing users
+- New buttons added in future will also default to on (deep-merge in `getSettings`)
+- Send and Attach File buttons are not hideable
+- Sticker still respects the existing `width < 500px` auto-hide on top of the setting
+
 ---
 
 ## Room Customization
@@ -691,6 +725,14 @@ A complete UI for managing Matrix push notification rules:
 - Delete button for removable rules
 - Add-rule form for creating new `room` and `sender` rules
 
+### Notification Profile Presets (P5-27)
+
+Three one-tap presets at the top of **Settings → Notifications** that apply a group of notification settings atomically:
+
+- **Gaming 🎮** — notifications on, all sounds off (`messageSoundId: none`, `inviteSoundId: none`)
+- **Work 💼** — all notifications and sounds on (restores defaults)
+- **Sleep 🌙** — all notifications off (`showNotifications: false`, sounds off)
+
 ---
 
 ## Server Integration