Design doc audit: update badges, fix outdated descriptions, add CDN/replication docs

Badge updates:
- BlobHeader: Planned → Complete (has receipt/comment slots, reactions, policy)
- LAN Discovery: Planned → Complete (iroh mDNS integration)
- UPnP TCP: Planned → Complete (both UDP+TCP renewal cycles)
- HTTP Post Delivery: added Complete badge

Description fixes:
- Share links: removed hostlist encoding, added tiered serving (redirect → punch → proxy)
- Eviction formula: added share_boost factor (+100 for 3+ downstream)
- Message types table: added ReplicationRequest/Response (0xE1/0xE2), count 41 → 49
- Engagement: added tombstone propagation description

New sections:
- Device roles & bandwidth budgets (Intermittent/Available/Persistent)
- Active CDN replication (10-min cycle, target prioritization, graceful degradation)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/app.js

@@ -357,6 +357,8 @@ function toast(msg) {
 
 // --- Notifications (Tauri plugin) ---
 let _notifReady = false;
+let _activeNotificationIds = new Set();
+
 async function maybeNotify(title, body, tag) {
     try {
         if (window.__TAURI__?.notification) {
@@ -367,16 +369,42 @@ async function maybeNotify(title, body, tag) {
                 granted = perm === 'granted';
             }
             if (granted) {
-                sendNotification({ title, body, channelId: 'default' });
+                sendNotification({ title, body, channelId: 'default', id: tag ? hashCode(tag) : undefined });
+                if (tag) _activeNotificationIds.add(tag);
             }
         } else if ('Notification' in window) {
-            // Fallback for browsers
             if (Notification.permission === 'default') await Notification.requestPermission();
             if (Notification.permission === 'granted') new Notification(title, { body, tag, silent: false });
         }
     } catch (_) {}
 }
 
+async function clearNotifications(tagPrefix) {
+    try {
+        if (window.__TAURI__?.notification) {
+            const { removeActive } = window.__TAURI__.notification;
+            if (!removeActive) return;
+            const toRemove = [..._activeNotificationIds].filter(t => t.startsWith(tagPrefix));
+            for (const tag of toRemove) {
+                try {
+                    await removeActive({ notifications: [{ id: hashCode(tag) }] });
+                } catch (_) {}
+                _activeNotificationIds.delete(tag);
+            }
+        }
+    } catch (_) {}
+}
+
+function hashCode(str) {
+    let hash = 0;
+    for (let i = 0; i < str.length; i++) {
+        const ch = str.charCodeAt(i);
+        hash = ((hash << 5) - hash) + ch;
+        hash |= 0;
+    }
+    return Math.abs(hash);
+}
+
 // --- Popover helpers ---
 let popoverOnClose = null;
 function openPopover(title, html, opts = {}) {
@@ -897,8 +925,9 @@ async function loadMessages(force) {
                             const input = $('#popover-reply-input');
                             if (input) setTimeout(() => input.focus(), 100);
 
-                            // Mark conversation as read (DB-backed)
+                            // Mark conversation as read (DB-backed) and clear notifications
                             invoke('mark_conversation_read', { partnerId }).catch(() => {});
+                            clearNotifications(`msg-`);
 
                             // Mark incoming encrypted messages as "seen"
                             for (const p of threadPosts) {
@@ -952,6 +981,7 @@ async function loadMessages(force) {
                         onClose() {
                             // Mark conversation as read when closing the popover
                             invoke('mark_conversation_read', { partnerId }).catch(() => {});
+                            clearNotifications(`msg-`);
                         }
                     });
                 });
@@ -2730,6 +2760,7 @@ document.querySelectorAll('.tab').forEach(tab => {
             if (target === 'messages') {
                 if (!conversationsList.children.length) conversationsList.innerHTML = renderLoading();
                 loadMessages(true); loadDmRecipientOptions();
+                clearNotifications('msg-');
             }
             if (target === 'settings') { loadRedundancy(); loadPublicVisible(); loadCacheSizeSetting(); }
         });