add run_pbwo4 C++ executable; fix missing std headers for Geant4 11.4

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

CMakeLists.txt

@@ -58,6 +58,9 @@ target_link_libraries(minicalo PUBLIC ${Geant4_LIBRARIES} ${Python3_LIBRARIES})
 add_executable(exampleB4a exampleB4a.cc ${sources} ${headers})
 target_link_libraries(exampleB4a ${Geant4_LIBRARIES} ${Python3_LIBRARIES})
 
+add_executable(run_pbwo4 run_pbwo4.cc ${sources} ${headers})
+target_link_libraries(run_pbwo4 ${Geant4_LIBRARIES} ${Python3_LIBRARIES})
+
 #----------------------------------------------------------------------------
 # Copy all scripts to the build directory, i.e. the directory in which we
 # build B4a. This is so that we can run the executable directly because it

include/PrimaryGeneratorAction.hh

@@ -32,6 +32,8 @@
 
 #include "G4VUserPrimaryGeneratorAction.hh"
 #include "globals.hh"
+#include <vector>
+#include <string>
 
 class G4ParticleGun;
 class G4Event;

include/RunAction.hh

@@ -32,6 +32,7 @@
 
 #include "G4UserRunAction.hh"
 #include "globals.hh"
+#include <vector>
 
 class G4Run;
 

run_pbwo4.cc

@@ -0,0 +1,36 @@
+#include "GeometryDescriptor.hh"
+#include "G4System.hh"
+
+#include <iostream>
+#include <string>
+#include <vector>
+
+int main(int argc, char** argv) {
+    int nEvents = 10;
+
+    if (argc > 2) {
+        std::cerr << "Usage: run_pbwo4 [nEvents]" << std::endl;
+        return 1;
+    }
+    if (argc == 2) {
+        try {
+            nEvents = std::stoi(argv[1]);
+            if (nEvents <= 0) throw std::invalid_argument("must be positive");
+        } catch (const std::exception& e) {
+            std::cerr << "Invalid nEvents '" << argv[1] << "': " << e.what() << std::endl;
+            return 1;
+        }
+    }
+
+    std::string outfile = "pbwo4_" + std::to_string(nEvents) + "events_hits.root";
+
+    GeometryDescriptor gd;
+    gd.addLayer(20.0, "G4_PbWO4", true, 10, 10);
+
+    G4System g4;
+    g4.init(gd, -1);
+    g4.run_batch(nEvents, {"e-"}, 1.0, 1.0, outfile);
+
+    std::cout << "Saved " << nEvents << " events to " << outfile << std::endl;
+    return 0;
+}