feat: Remind Me Later, mobile bookmarks, bug fixes, and doc cleanup

Features:
- Remind Me Later: message context menu item opens a preset time picker
  (20 min / 1 hr / 3 hr / tomorrow 9am); reminders persist to Matrix
  account data (io.lotus.reminders); ReminderMonitor fires a Lotus Toast
  when due, checks every 30s and on tab focus
- Mobile Bookmarks: BookmarksPanel now renders on all screen sizes;
  passes isMobile prop for full-screen absolute overlay on mobile

Bug fixes:
- usePan.ts: memory leak from stale closure in document listener cleanup
- EventReaders.tsx: replace hardcoded hex colors with TDS CSS variables
- CallControls.tsx: replace hardcoded hex colors with TDS CSS variables
- CustomHtml.css.ts: replace hardcoded yellow/black highlight with theme tokens

Docs:
- LOTUS_TODO.md: restore deleted content (Confirmed facts table, Pending
  Audits, P5-30 completed status, full feature descriptions), keep new
  additions (P4-7/8/9, P5-41–57, Implementation Reference), eliminate
  duplicate sections
- LOTUS_BUGS.md: merge RESILIENCE_AUDIT.md findings into Architectural &
  Resilience Audit table; delete RESILIENCE_AUDIT.md
- Remove stale LOTUS_DENOISE_ENGINEERING_REVIEW.md and LOTUS_TODO_REFERENCE.md

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

src/app/pages/client/ClientLayout.tsx

@@ -44,10 +44,15 @@ export function ClientLayout({ nav, children }: ClientLayoutProps) {
         <Box grow="Yes" as="main" id="main-content">
           {children}
         </Box>
-        {bookmarksOpen && screenSize === ScreenSize.Desktop && (
+        {bookmarksOpen && (
           <>
-            <Line variant="Background" direction="Vertical" size="300" />
-            <BookmarksPanel onClose={() => setBookmarksOpen(false)} />
+            {screenSize === ScreenSize.Desktop && (
+              <Line variant="Background" direction="Vertical" size="300" />
+            )}
+            <BookmarksPanel
+              onClose={() => setBookmarksOpen(false)}
+              isMobile={screenSize !== ScreenSize.Desktop}
+            />
           </>
         )}
       </Box>