feat: show unread message count on chat tabs

Each non-General chat tab now shows an unread count in parentheses
(e.g. "Whispers (3)") when messages arrive while that tab is inactive.
The counter clears when the tab is selected. The General tab is excluded
since it shows all messages anyway.

include/ui/game_screen.hpp

@@ -70,6 +70,8 @@ private:
         uint64_t typeMask;  // bitmask of ChatType values to show (64-bit: types go up to 84)
     };
     std::vector<ChatTab> chatTabs_;
+    std::vector<int> chatTabUnread_;   // unread message count per tab (0 = none)
+    size_t chatTabSeenCount_ = 0;      // how many history messages have been processed
     void initChatTabs();
     bool shouldShowMessage(const game::MessageChatData& msg, int tabIndex) const;
 

src/ui/game_screen.cpp

@@ -228,6 +228,9 @@ void GameScreen::initChatTabs() {
                                    (1ULL << static_cast<uint8_t>(game::ChatType::GUILD_ACHIEVEMENT))});
     // Trade/LFG tab: channel messages
     chatTabs_.push_back({"Trade/LFG", (1ULL << static_cast<uint8_t>(game::ChatType::CHANNEL))});
+    // Reset unread counts to match new tab list
+    chatTabUnread_.assign(chatTabs_.size(), 0);
+    chatTabSeenCount_ = 0;
 }
 
 bool GameScreen::shouldShowMessage(const game::MessageChatData& msg, int tabIndex) const {
@@ -1107,11 +1110,43 @@ void GameScreen::renderChatWindow(game::GameHandler& gameHandler) {
         chatWindowPos_ = ImGui::GetWindowPos();
     }
 
+    // Update unread counts: scan any new messages since last frame
+    {
+        const auto& history = gameHandler.getChatHistory();
+        // Ensure unread array is sized correctly (guards against late init)
+        if (chatTabUnread_.size() != chatTabs_.size())
+            chatTabUnread_.assign(chatTabs_.size(), 0);
+        // If history shrank (e.g. cleared), reset
+        if (chatTabSeenCount_ > history.size()) chatTabSeenCount_ = 0;
+        for (size_t mi = chatTabSeenCount_; mi < history.size(); ++mi) {
+            const auto& msg = history[mi];
+            // For each non-General (non-0) tab that isn't currently active, check visibility
+            for (int ti = 1; ti < static_cast<int>(chatTabs_.size()); ++ti) {
+                if (ti == activeChatTab_) continue;
+                if (shouldShowMessage(msg, ti)) {
+                    chatTabUnread_[ti]++;
+                }
+            }
+        }
+        chatTabSeenCount_ = history.size();
+    }
+
     // Chat tabs
     if (ImGui::BeginTabBar("ChatTabs")) {
         for (int i = 0; i < static_cast<int>(chatTabs_.size()); ++i) {
-            if (ImGui::BeginTabItem(chatTabs_[i].name.c_str())) {
+            // Build label with unread count suffix for non-General tabs
-                activeChatTab_ = i;
+            std::string tabLabel = chatTabs_[i].name;
+            if (i > 0 && i < static_cast<int>(chatTabUnread_.size()) && chatTabUnread_[i] > 0) {
+                tabLabel += " (" + std::to_string(chatTabUnread_[i]) + ")";
+            }
+            // Use ImGuiTabItemFlags_NoPushId so label changes don't break tab identity
+            if (ImGui::BeginTabItem(tabLabel.c_str())) {
+                if (activeChatTab_ != i) {
+                    activeChatTab_ = i;
+                    // Clear unread count when tab becomes active
+                    if (i < static_cast<int>(chatTabUnread_.size()))
+                        chatTabUnread_[i] = 0;
+                }
                 ImGui::EndTabItem();
             }
         }