docs: document desktop features (Tier A + B) across catalog/README/TODO

- LOTUS_FEATURES.md: new "Desktop App Features" section (+ TOC) covering all
  desktop capabilities — no-sleep, jump list, thumbbar, SMTC, network awareness,
  rich notifications, Focus Assist, window chrome, update toast, toolbar reorder,
  draft indicator, recursive folder DnD.
- README.md: "Desktop-Specific Features" bullets under the Desktop App section.
- LOTUS_TODO.md: P5-35/41/56 → [~] IMPLEMENTED (Tier B); P5-48 → [~] (recursive
  folder upload; .lnk/Send-To scoped-out with rationale).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

LOTUS_TODO.md

@@ -334,7 +334,7 @@ Features:
 
 ---
 
-### [ ] P5-35 · Desktop — Notification Click Opens Room (DEFERRED)
+### [~] P5-35 · Desktop — Notification Click Opens Room — IMPLEMENTED (Tier B, via the P5-41 WinRT toast: click → open room, reply → send); native CI-compile-pending, runtime-verify on Windows
 
 **What:** Clicking a system tray notification navigates to the relevant room. Quick-reply from the notification toast would send the reply without opening the window.  
 **Status:** Deferred (Tier B). Note: the "can't compile-test without a Windows build environment" premise is **outdated** — CI now compiles Windows (Gitea self-hosted `windows` runner + GitHub `windows-latest`), and `windows`-crate/COM code already ships (e.g. `set_badge_count`, and the Tier A jump list). This still depends on P5-41 (the WinRT toast + custom activator), so it rides with that; it was not part of the Tier A wave.  
@@ -352,7 +352,7 @@ Features:
 
 ---
 
-### [ ] P5-41 · Desktop — Native WinRT Toast Notifications
+### [~] P5-41 · Desktop — Native WinRT Toast Notifications — IMPLEMENTED (Tier B; ToastNotification + reply input + in-process Activated; falls back to tauri-plugin-notification); native CI-compile-pending. Runtime needs a Start-menu shortcut + matching AppUserModelID to surface
 
 **What:** Replace emulated notifications with native WinRT Toast notifications.  
 **Approach:** Implement native WinRT Toast integration using `windows-rs` to enable full Action Center integration, including native Quick Reply functionality.
@@ -382,7 +382,7 @@ Features:
 **What:** Replace system titlebar with custom Lotus TDS chrome.  
 **Approach:** Configure Tauri window (`decorations: false`) and implement custom, TDS-token compliant titlebar controls (Close/Max/Min) for a cohesive UI.
 
-### [ ] P5-48 · Desktop — Native File System Drag-and-Drop Improvements
+### [~] P5-48 · Desktop — Native File System Drag-and-Drop Improvements — IMPLEMENTED (recursive folder upload, web-verified: tsc/build/tests). SCOPED-OUT: `.lnk` shortcut resolution (webview never exposes a dropped file's OS path → native can't resolve the target) and "Send To" (installer/registry shell integration) — deferred
 
 **What:** Enhance drag-and-drop support for Windows.  
 **Approach:** Improve handling for Windows file shortcuts, recursive folder uploads, and shell-integrated "Send To" context menu actions.
@@ -418,7 +418,7 @@ Features:
 **What:** Allow users to reorder toolbar icons via drag-and-drop.  
 **Approach:** Extend the current settings-based toolbar toggle system to include a drag-and-drop UI mode in the composer settings, allowing users to personalize their icon order.
 
-### [ ] P5-56 · Desktop — Windows "Focus Assist" (DND) Sync
+### [~] P5-56 · Desktop — Windows "Focus Assist" (DND) Sync — IMPLEMENTED (Tier B; SHQueryUserNotificationState poll → suppresses notifications+sounds via the quiet-hours gate); native CI-compile-pending, runtime-verify on Windows
 
 **What:** Automatically toggle notification state based on Windows Focus Assist.  
 **Approach:** Integrate with the Windows `NotificationCenter` / `Focus` state via Tauri/Rust to automatically enable/disable Lotus Chat's internal notification suppression mode when Windows Focus Assist is toggled.