Add shared reasource tag to allow coordination of usage

include/kpn/static_network.hpp

@@ -13,6 +13,7 @@
 #endif
 
 #include <iostream>
+#include <map>
 #include <string>
 #include <tuple>
 #include <type_traits>
@@ -113,7 +114,7 @@ public:
             web_debug_port_,
             [this]() {
                 auto s = collect_snapshots();
-                return web_debug::to_json(s.nodes, s.channels, s.elapsed_s);
+                return web_debug::to_json(s.nodes, s.channels, s.resources, s.elapsed_s);
             });
         web_server_->start();
         std::cerr << "[kpn] web debug UI: http://localhost:" << web_debug_port_ << "\n";
@@ -143,6 +144,12 @@ public:
     void set_web_debug_port(uint16_t port) { web_debug_port_ = port; }
 #endif
 
+    // Register a shared resource so it appears in diagnostics and the debug UI.
+    // The probe must outlive this network (typically the resource is on the same stack).
+    void register_resource(const std::string& name, IResourceProbe* probe) {
+        resource_probes_.emplace_back(name, probe);
+    }
+
     // Print diagnostics using compile-time node labels
     void print_diagnostics(std::ostream& os = std::cerr) const {
         os << "\n┌─ KPN++ StaticNetwork diagnostics ─────────────────────────────\n";
@@ -159,9 +166,10 @@ public:
 
 private:
     struct Snapshots {
-        std::vector<NodeSnapshot>    nodes;
-        std::vector<ChannelSnapshot> channels;
-        double                       elapsed_s;
+        std::vector<NodeSnapshot>     nodes;
+        std::vector<ChannelSnapshot>  channels;
+        std::vector<ResourceSnapshot> resources;
+        double                        elapsed_s;
     };
 
     Snapshots collect_snapshots() const {
@@ -178,7 +186,11 @@ private:
         for (auto& probe : channel_probes_)
             channels.push_back(probe->snapshot());
 
-        return {std::move(nodes), std::move(channels), elapsed_s};
+        std::vector<ResourceSnapshot> resources;
+        for (auto& [name, probe] : resource_probes_)
+            resources.push_back(probe->snapshot(name));
+
+        return {std::move(nodes), std::move(channels), std::move(resources), elapsed_s};
     }
 
     std::string                                         name_;
@@ -189,6 +201,7 @@ private:
     std::vector<std::string>                            user_node_names_;
     std::vector<std::string>                            fanout_node_names_;
     std::vector<std::unique_ptr<IChannelProbe>>         channel_probes_;
+    std::vector<std::pair<std::string, IResourceProbe*>> resource_probes_;
     clock_t::time_point                                 start_time_;
 #ifdef KPN_WEB_DEBUG
     uint16_t                                            web_debug_port_{9090};