[SIM] Added Geant4 headers to custom physics

[civanch]

PR description:

In old hadronic model used by CustomPhysics package some Geant4 headers were not explicit. It is fixed in this PR. No effect to any work flow. Fix of cms-sw/cmsdist#10558

PR validation:

Compiles

If this PR is a backport please specify the original PR and why you need to backport that PR. If this PR will be backported please specify to which release cycle the backport is meant for: NO

[civanch]

type bugfix

[cmsbuild]

cms-bot internal usage

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-50950/49357

[cmsbuild]

A new Pull Request was created by @civanch for master.

It involves the following packages:

• SimG4Core/CustomPhysics (simulation)

@civanch, @cmsbuild, @kpedro88, @mdhildreth can you please review it and eventually sign? Thanks.
@bsunanda, @fabiocos, @makortel, @martinamalberti, @rovere, @slomeo this is something you requested to watch as well.
@ftenchini, @mandrenguyen, @sextonkennedy you are the release manager for this.

cms-bot commands are listed here

[civanch]

please test

[cmsbuild]

+1

Size: This PR adds an extra 48KB to repository
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-4efd01/53273/summary.html
COMMIT: 878d777
CMSSW: CMSSW_17_0_X_2026-05-15-1100/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/50950/53273/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially added 2 lines to the logs
• ROOTFileChecks: Some differences in event products or their sizes found
• Reco comparison results: 9 differences found in the comparisons
• DQMHistoTests: Total files compared: 53
• DQMHistoTests: Total histograms compared: 4187168
• DQMHistoTests: Total failures: 26
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 4187122
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 52 files compared)
• Checked 227 log files, 197 edm output root files, 53 DQM output files
• TriggerResults: no differences found

[civanch]

+1

This is pure technical update, which is valid anyway.

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next master IBs (tests are also fine). This pull request will now be reviewed by the release team before it's merged. @sextonkennedy, @mandrenguyen, @ftenchini (and backports should be raised in the release meeting by the corresponding L2)