Address code review comments: rename thresholds and remove unnecessary copy

Changes based on code review feedback from vkucera:

1. Rename threshold constants to follow "quantity + object" naming pattern:
   - FT0AThreshold → AmplitudeThresholdFT0A
   - FT0CThreshold → AmplitudeThresholdFT0C
   - ZDCThreshold → EnergyThresholdZDC

   Updated function parameters and all usages in utilsUpcHf.h.

2. Remove unnecessary centrality copy in UPC process function:
   - Removed `float cent{centrality};` declaration
   - Use `centrality` variable directly throughout the function

   This eliminates redundant variable and improves code clarity.

3. Use literal values for Configurable defaults:
   - Configurables require literal values, not constexpr references
   - Changed from using defaults namespace to 100.0f, 50.0f, 1.0f

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: minjungkim12

PWGHF/D2H/Tasks/taskDplus.cxx

@@ -85,9 +85,9 @@ struct HfTaskDplus {
   Configurable<std::string> ccdbPathGrpMag{"ccdbPathGrpMag", "GLO/Config/GRPMagField", "CCDB path of the GRPMagField object (Run 3)"};
 
   // UPC gap determination thresholds
-  Configurable<float> upcFT0AThreshold{"upcFT0AThreshold", hf_upc::defaults::FT0AThreshold, "FT0-A amplitude threshold for UPC gap determination (a.u.)"};
-  Configurable<float> upcFT0CThreshold{"upcFT0CThreshold", hf_upc::defaults::FT0CThreshold, "FT0-C amplitude threshold for UPC gap determination (a.u.)"};
-  Configurable<float> upcZDCThreshold{"upcZDCThreshold", hf_upc::defaults::ZDCThreshold, "ZDC energy threshold for UPC gap determination (a.u.)"};
+  Configurable<float> upcFT0AThreshold{"upcFT0AThreshold", 100.0f, "FT0-A amplitude threshold for UPC gap determination (a.u.)"};
+  Configurable<float> upcFT0CThreshold{"upcFT0CThreshold", 50.0f, "FT0-C amplitude threshold for UPC gap determination (a.u.)"};
+  Configurable<float> upcZDCThreshold{"upcZDCThreshold", 1.0f, "ZDC energy threshold for UPC gap determination (a.u.)"};
 
   HfEventSelection hfEvSel; // event selection and monitoring
 

PWGHF/Utils/utilsUpcHf.h

@@ -32,34 +32,34 @@ enum class GapType : uint8_t {
 /// \brief Default thresholds for gap determination
 namespace defaults
 {
-constexpr float FT0AThreshold = 100.0f; ///< FT0-A amplitude threshold (a.u.)
-constexpr float FT0CThreshold = 50.0f;  ///< FT0-C amplitude threshold (a.u.)
-constexpr float ZDCThreshold = 1.0f;    ///< ZDC energy threshold (a.u.)
+constexpr float AmplitudeThresholdFT0A = 100.0f; ///< Amplitude threshold for FT0-A (a.u.)
+constexpr float AmplitudeThresholdFT0C = 50.0f;  ///< Amplitude threshold for FT0-C (a.u.)
+constexpr float EnergyThresholdZDC = 1.0f;       ///< Energy threshold for ZDC (a.u.)
 } // namespace defaults
 
 /// \brief Determine gap type based on FIT and ZDC signals
 /// \param ft0A FT0-A amplitude
 /// \param ft0C FT0-C amplitude
 /// \param zdcA ZDC-A (ZNA) common energy
 /// \param zdcC ZDC-C (ZNC) common energy
-/// \param ft0AThreshold Threshold for FT0-A (default: 100.0)
-/// \param ft0CThreshold Threshold for FT0-C (default: 50.0)
-/// \param zdcThreshold Threshold for ZDC (default: 1.0)
+/// \param amplitudeThresholdFT0A Threshold for FT0-A (default: 100.0)
+/// \param amplitudeThresholdFT0C Threshold for FT0-C (default: 50.0)
+/// \param energyThresholdZDC Threshold for ZDC (default: 1.0)
 /// \return Gap type classification
 inline GapType determineGapType(float ft0A, float ft0C, float zdcA, float zdcC,
-                                float ft0AThreshold = defaults::FT0AThreshold,
-                                float ft0CThreshold = defaults::FT0CThreshold,
-                                float zdcThreshold = defaults::ZDCThreshold)
+                                float amplitudeThresholdFT0A = defaults::AmplitudeThresholdFT0A,
+                                float amplitudeThresholdFT0C = defaults::AmplitudeThresholdFT0C,
+                                float energyThresholdZDC = defaults::EnergyThresholdZDC)
 {
   // Gap on A-side: FT0-A empty, FT0-C active, ZNA empty, ZNC active
-  if (ft0A < ft0AThreshold && ft0C > ft0CThreshold &&
-      zdcA < zdcThreshold && zdcC > zdcThreshold) {
+  if (ft0A < amplitudeThresholdFT0A && ft0C > amplitudeThresholdFT0C &&
+      zdcA < energyThresholdZDC && zdcC > energyThresholdZDC) {
     return GapType::GapA;
   }
 
   // Gap on C-side: FT0-A active, FT0-C empty, ZNA active, ZNC empty
-  if (ft0A > ft0AThreshold && ft0C < ft0CThreshold &&
-      zdcA > zdcThreshold && zdcC < zdcThreshold) {
+  if (ft0A > amplitudeThresholdFT0A && ft0C < amplitudeThresholdFT0C &&
+      zdcA > energyThresholdZDC && zdcC < energyThresholdZDC) {
     return GapType::GapC;
   }