[PWGCF] Femto: Add D0 meson support to the femto framework

[IgorPtak]

Adds D0 mesons as a new particle species to the unified femto framework, enabling D0-hadron femtoscopic correlations.

What is added

Data model - three new tables:

• FD0s - kinematics, mass of the accepted hypothesis and daughter indices
• FD0Masks - selection bitmask
• FD0Extras - QA/debug: both mass hypotheses, topological variables, BDT scores and the PWGHF selection flags
• FD0Labels - MC labels

Core: charmHadronBuilder.h and charmHadronHistManager.h, following the structure of the existing V0/cascade builders. D0 candidates are taken from PWGHF (HfCand2Prong), with the acceptance applied as a rapidity cut via HfHelper. The D0/D0bar hypothesis is encoded in the sign of the stored signed pT.

Tasks: two new workflows:

• femto-d0-qa - QA for D0 candidates and their daughters
• femto-pair-track-d0 - D0-hadron correlations, same and mixed event

MC: D0 candidates have no direct MC label, so both prongs are matched to a generated D0 -> K pi decay with RecoDecay::getMatchedMCRec. Charm hadrons are additionally classified as prompt or non-prompt, which required extending the McOrigin enum.

[github-actions]

O2 linter results: ❌ 0 errors, ⚠️ 0 warnings, 🔕 0 disabled

[alibuild]

Error while checking build/O2Physics/code-check for e6b7555 at 2026-07-29 19:46:

## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 9 errors and 2 warnings.'
Found 9 errors and 2 warnings.
++ [[ 9 -gt 0 ]]
++ cat /sw/BUILD/0f9cdfd2185751249e7c2c145bfdaaf9ce837c70/O2Physics-code-check/errors.txt
PWGCF/Femto/Core/charmHadronBuilder.h:25:1: error: included header CandidateReconstructionTables.h is not used directly [misc-include-cleaner,-warnings-as-errors]
PWGCF/Femto/Core/charmHadronBuilder.h:67:36: error: no header providing "std::vector" is directly included [misc-include-cleaner,-warnings-as-errors]
PWGCF/Femto/Core/charmHadronBuilder.h:166:92: error: no header providing "o2::analysis::femto::limits::kLowerLimit" is directly included [misc-include-cleaner,-warnings-as-errors]
PWGCF/Femto/Core/charmHadronBuilder.h:168:149: error: no header providing "o2::analysis::femto::limits::kUpperLimit" is directly included [misc-include-cleaner,-warnings-as-errors]
PWGCF/Femto/Core/charmHadronBuilder.h:169:119: error: no header providing "o2::analysis::femto::limits::kAbsUpperLimit" is directly included [misc-include-cleaner,-warnings-as-errors]
PWGCF/Femto/Core/charmHadronBuilder.h:318:49: error: no header providing "int64_t" is directly included [misc-include-cleaner,-warnings-as-errors]
PWGCF/Femto/Core/charmHadronBuilder.h:348:21: error: no header providing "int8_t" is directly included [misc-include-cleaner,-warnings-as-errors]
PWGCF/Femto/Core/charmHadronHistManager.h:34:1: error: included header cstddef is not used directly [misc-include-cleaner,-warnings-as-errors]
PWGCF/Femto/Core/mcBuilder.h:246:102: error: no header providing "std::array" is directly included [misc-include-cleaner,-warnings-as-errors]
++ [[ 2 -gt 0 ]]
++ cat /sw/BUILD/0f9cdfd2185751249e7c2c145bfdaaf9ce837c70/O2Physics-code-check/warnings.txt
PWGCF/Femto/TableProducer/femtoProducer.cxx:389:71: warning: statement should be inside braces [readability-braces-around-statements]
PWGCF/Femto/TableProducer/femtoProducer.cxx:403:73: warning: statement should be inside braces [readability-braces-around-statements]
++ [[ 9 -gt 0 ]]
++ exit 1
--

Full log here.

[alibuild]

Error while checking build/O2Physics/o2 for 06079ed at 2026-07-30 02:27:

## sw/BUILD/O2Physics-latest/log
c++: fatal error: Killed signal terminated program cc1plus
c++: fatal error: Killed signal terminated program cc1plus
ninja: build stopped: subcommand failed.

Full log here.