Complete city production queue implementation

city.h

@@ -55,6 +55,7 @@ public:
     int accumulatedLabor = 0; // Local resource (Arbeid)
 
     CityProject currentProject;
+    std::vector<CityProject> projectQueue;
     std::vector<QString> completedBuildings; // IDs of completed buildings in the city
 
     std::vector<std::pair<int, int>> territory; // Owned hex coordinates
@@ -77,6 +78,34 @@ public:
         return true;
     }
 
+    bool isBuildingQueuedOrBuilt(const QString &buildingId) const {
+        if (hasBuilding(buildingId)) return true;
+        if (currentProject.isValid() && currentProject.type == CityProjectType::Building && currentProject.id == buildingId) return true;
+        for (const auto &q : projectQueue) {
+            if (q.type == CityProjectType::Building && q.id == buildingId) return true;
+        }
+        return false;
+    }
+
+    int getQueuedBuildingPosition(const QString &buildingId) const {
+        for (size_t i = 0; i < projectQueue.size(); ++i) {
+            if (projectQueue[i].type == CityProjectType::Building && projectQueue[i].id == buildingId) {
+                return (int)i + 1;
+            }
+        }
+        return 0;
+    }
+
+    int getQueuedUnitCount(const QString &unitId) const {
+        int count = 0;
+        for (const auto &q : projectQueue) {
+            if (q.type == CityProjectType::Unit && q.id == unitId) {
+                count++;
+            }
+        }
+        return count;
+    }
+
     bool hasActiveProject() const {
         return currentProject.isValid();
     }
@@ -90,8 +119,53 @@ public:
         currentProject.district = district.isEmpty() ? "center" : district;
     }
 
+    bool queueProject(CityProjectType type, const QString &projId, const QString &projName, int cost, const QString &district = "center", int maxQueueSize = 6) {
+        if (!hasActiveProject()) {
+            startProject(type, projId, projName, cost, district);
+            return true;
+        }
+        if ((int)projectQueue.size() >= maxQueueSize) {
+            return false;
+        }
+        CityProject q;
+        q.type = type;
+        q.id = projId;
+        q.name = projName;
+        q.laborCost = std::max(1, cost);
+        q.currentLabor = 0;
+        q.district = district.isEmpty() ? "center" : district;
+        projectQueue.push_back(q);
+        return true;
+    }
+
+    void cancelActiveProject() {
+        if (!projectQueue.empty()) {
+            currentProject = projectQueue.front();
+            projectQueue.erase(projectQueue.begin());
+        } else {
+            currentProject = CityProject();
+        }
+    }
+
     void cancelProject() {
-        currentProject = CityProject();
+        cancelActiveProject();
+    }
+
+    bool removeQueuedProject(int index) {
+        if (index >= 0 && index < (int)projectQueue.size()) {
+            projectQueue.erase(projectQueue.begin() + index);
+            return true;
+        }
+        return false;
+    }
+
+    void advanceQueue() {
+        if (!projectQueue.empty()) {
+            currentProject = projectQueue.front();
+            projectQueue.erase(projectQueue.begin());
+        } else {
+            currentProject = CityProject();
+        }
     }
 
     bool addTerritory(int tx, int ty) {