fix(esolver): manage dftu_ via std::unique_ptr to prevent memory leak

ESolver_KS::dftu_ was allocated with new in both ESolver_KS_PW and
ESolver_KS_LCAO constructors but never deleted in ~ESolver_KS,
contradicting the member comment and commit 156a5d8. Convert dftu_
to std::unique_ptr<Plus_U_Base> so ownership is explicit and the
object is released automatically on destruction.

Call sites that pass raw pointers to downstream functions use .get();
C++11 baseline requires reset(new ...) instead of std::make_unique.

Author: abacus_fixer

source/source_esolver/esolver_dfpt_pw.cpp

@@ -354,7 +354,7 @@ void ESolver_DFPT_PW::init_dfpt(UnitCell& ucell)
 
     dfpt_->init(ucell, *this->stp.psi_cpu, this->pw_rho, this->pw_wfc, &this->sf, veff_r,
                 this->pelec->wg, this->pelec->ekb, xc_adapter_, nelec_, ecutwfc_,
-                dft_plus_u_ ? this->dftu_ : nullptr);
+                dft_plus_u_ ? this->dftu_.get() : nullptr);
 }
 
 void ESolver_DFPT_PW::run_post_process(UnitCell& ucell)

source/source_esolver/esolver_double_xc.cpp

@@ -148,7 +148,7 @@ void ESolver_DoubleXC<TK, TR>::before_scf(UnitCell& ucell, const int istep)
                                                              this->two_center_bundle_,
                                                              this->orb_,
                                                              this->dmat_base.dm,
-                                                             this->dftu_,
+                                                             this->dftu_.get(),
                                                              this->deepks,
                                                              istep,
                                                              this->exx_nao,

source/source_esolver/esolver_ks.h

@@ -60,9 +60,9 @@ class ESolver_KS : public ESolver_FP
     //! nonlocal pseudopotentials
     pseudopot_cell_vnl ppcell;
 
-    //! DFT+U method (base-class pointer; PW news Plus_U_Base, LCAO news Plus_U),
-    //! allocated in the derived-class constructor, deleted in ~ESolver_KS.
-    Plus_U_Base* dftu_ = nullptr;
+    //! DFT+U method (base-class pointer; PW news Plus_U_Base, LCAO news Plus_U).
+    //! Owned by ESolver_KS via unique_ptr; released automatically in ~ESolver_KS.
+    std::unique_ptr<Plus_U_Base> dftu_;
 
     std::string basisname;          //! esolver_ks_lcao.cpp
     double esolver_KS_ne = 0.0;     //! number of electrons

source/source_esolver/esolver_ks_lcao.cpp

@@ -36,7 +36,7 @@ ESolver_KS_LCAO<TK, TR>::ESolver_KS_LCAO()
 {
     this->classname = "ESolver_KS_LCAO";
     this->basisname = "LCAO";
-    this->dftu_ = new Plus_U();
+    this->dftu_.reset(new Plus_U());
 }
 
 template <typename TK, typename TR>
@@ -158,7 +158,7 @@ void ESolver_KS_LCAO<TK, TR>::before_scf(UnitCell& ucell, const int istep)
     {
         this->p_hamilt = new hamilt::HamiltLCAO<TK, TR>(
             ucell, this->gd, &this->pv, this->pelec->pot, this->kv,
-            two_center_bundle_, orb_, this->dmat.dm, this->dftu_, this->deepks, istep, exx_nao, this->exx_info_);
+            two_center_bundle_, orb_, this->dmat.dm, this->dftu_.get(), this->deepks, istep, exx_nao, this->exx_info_);
     }
 
     // 9) for each ionic step, the overlap <phi|alpha> must be rebuilt
@@ -510,7 +510,7 @@ void ESolver_KS_LCAO<TK, TR>::iter_finish(UnitCell& ucell, const int istep, int&
 	const std::vector<std::vector<TK>>& dm_vec = this->dmat.dm->get_DMK_vector();
 
     // 1) calculate the local occupation number matrix and energy correction in DFT+U
-    finish_dftu_lcao<TK>(iter, conv_esolver, this->inp_->dft_plus_u, this->inp_->out_chg[0], this->dftu_, ucell, dm_vec, this->kv, this->p_chgmix->get_mixing_beta(), hamilt_lcao, PARAM.globalv.global_out_dir, this->inp_->nspin, PARAM.globalv.npol, PARAM.globalv.gamma_only_local);
+    finish_dftu_lcao<TK>(iter, conv_esolver, this->inp_->dft_plus_u, this->inp_->out_chg[0], this->dftu_.get(), ucell, dm_vec, this->kv, this->p_chgmix->get_mixing_beta(), hamilt_lcao, PARAM.globalv.global_out_dir, this->inp_->nspin, PARAM.globalv.npol, PARAM.globalv.gamma_only_local);
 
     // mohan add 2025-11: push DFT+U energy from Plus_U instance to ElecState.
     // Covers both dft_plus_u==1 (new method, energy accumulated by DFTU::contributeHR

source/source_esolver/esolver_ks_pw.cpp

@@ -33,7 +33,7 @@ ESolver_KS_PW<T, Device>::ESolver_KS_PW()
     this->classname = "ESolver_KS_PW";
     this->basisname = "PW";
     // PW basis: the DFT+U object is the base class (no LCAO orbitals).
-    this->dftu_ = new Plus_U_Base();
+    this->dftu_.reset(new Plus_U_Base());
 }
 
 template <typename T, typename Device>
@@ -67,7 +67,7 @@ void ESolver_KS_PW<T, Device>::allocate_hamilt(const UnitCell& ucell)
                                                      this->pw_wfc,
                                                      &this->kv,
                                                      &this->ppcell,
-                                                     this->dftu_,
+                                                     this->dftu_.get(),
                                                      &ucell,
                                                      &this->general_exx_info_);
 }
@@ -385,7 +385,7 @@ void ESolver_KS_PW<T, Device>::cal_force(BaseCell& basecell, ModuleBase::matrix&
                  &ucell.symm,
                  &this->sf,
                  this->solvent,
-                 this->dftu_,
+                 this->dftu_.get(),
                  &this->locpp,
                  &this->ppcell,
                  &this->kv,

source/source_esolver/lcao_others.cpp

@@ -133,7 +133,7 @@ void ESolver_KS_LCAO<TK, TR>::others(BaseCell& basecell, const int istep)
                                                         two_center_bundle_,
                                                         orb_,
                                                         this->dmat.dm,
-                                                        this->dftu_,
+                                                        this->dftu_.get(),
                                                         this->deepks,
                                                         istep,
                                                         this->exx_nao,