[lanshuyue]

Summary

• Initialize the per-ionic-step DFT+U occupation-matrix output in shared ESolver_KS::iter_init() for both PW and LCAO.
• Remove the duplicate preparation calls and file-output parameters from iter_init_dftu_pw() and finish_dftu_lcao().

Verification

• CMake configured successfully with IntelLLVM 2024, MPI, LCAO, and tests enabled.
• Syntax compilation passed for all five changed C++ translation units using the configured compiler.
• OMP_NUM_THREADS=1 ctest --test-dir /home/lanshuyue/abacus/ABACUS/abacus-develop/build --output-on-failure -R '^(MODULE_PW_dftu_base_test|MODULE_DFTU_base_io)$': 2/2 passed outside the restricted process environment. These are existing binaries from the neighboring checkout, so they validate the existing DFT+U I/O behavior but do not exercise the newly built solver.
• python3 tools/03_code_analysis/agent_governance_check.py --staged: no errors; warnings addressed below.
• git diff --check: passed.

Review notes

• The PARAM.globalv.global_out_dir reference moved from the PW solver call site to the shared KS solver; the PR-wide global dependency count is unchanged. The shared output entry point still needs this directory until it is passed through a broader solver configuration change.
• No INPUT behavior or documentation format changes. The user-visible occupation-matrix output is prepared earlier in each SCF iteration, including LCAO, as requested.
• No new test fixture was added because the existing I/O tests cover file initialization, while constructing an ESolver_KS fixture would expand this small orchestration change substantially. Full PW/LCAO runtime validation remains for CI/review.