Add chat widget improvements and chat history component

Widget improvements:
- Pulsating badge with unread message count on floating button
- Clickable ticket reference link in chat header
- ExternalLink icon on hover

Desktop (Raven) improvements:
- Track previous unread count for new message detection
- Send native Windows notifications for new messages
- Focus chat window when new messages arrive

Chat history:
- New query getTicketChatHistory for fetching chat sessions and messages
- New component TicketChatHistory displaying chat sessions
- Sessions can be expanded/collapsed to view messages
- Pagination support for long conversations
- Added to both dashboard and portal ticket views

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/components/chat/chat-widget.tsx

@@ -29,6 +29,7 @@ import {
   FileText,
   Image as ImageIcon,
   Download,
+  ExternalLink,
 } from "lucide-react"
 
 const MAX_MESSAGE_LENGTH = 4000
@@ -444,10 +445,16 @@ export function ChatWidget() {
                   )}
                 </div>
                 {activeSession && (
-                  <p className="text-xs text-slate-500">
-                    #{activeSession.ticketRef}
-                    {machineHostname && ` - ${machineHostname}`}
-                  </p>
+                  <a
+                    href={`/dashboard/tickets/${activeTicketId}`}
+                    target="_blank"
+                    rel="noopener noreferrer"
+                    className="group flex items-center gap-1 text-xs text-slate-500 hover:text-primary transition-colors"
+                  >
+                    <span>#{activeSession.ticketRef}</span>
+                    {machineHostname && <span> - {machineHostname}</span>}
+                    <ExternalLink className="size-3 opacity-0 group-hover:opacity-100 transition-opacity" />
+                  </a>
                 )}
               </div>
             </div>
@@ -725,9 +732,15 @@ export function ChatWidget() {
         >
           <MessageCircle className="size-6" />
           {totalUnread > 0 && (
-            <span className="absolute -right-1 -top-1 flex size-6 items-center justify-center rounded-full bg-red-500 text-xs font-bold">
-              {totalUnread}
-            </span>
+            <>
+              {/* Anel pulsante externo */}
+              <span className="absolute -right-1 -top-1 flex size-6 items-center justify-center">
+                <span className="absolute inline-flex size-full animate-ping rounded-full bg-red-400 opacity-75" />
+                <span className="relative flex size-6 items-center justify-center rounded-full bg-red-500 text-xs font-bold text-white">
+                  {totalUnread > 99 ? "99+" : totalUnread}
+                </span>
+              </span>
+            </>
           )}
         </button>
       )}