source_basis/module_ao: orb_atomic_lm_test off the access hack, via getters plus one friend (#7953)

`orb_atomic_lm_test.cpp` reached into 17 private members of
`Numerical_Orbital_Lm` and called four of its private methods. Sixteen of those
members already have public accessors, so the macro comes off mostly by using
them: 138 sites now read through `get_psi()`, `getNr()`, `getRcut()` and the
rest. No PARAM is involved.

Two things needed more than a substitution:

- `psir` was the only array in the class without the vector accessor its
  siblings all have. `Numerical_Orbital_Lm` exposes a systematic trio per array
  -- `getX()` returning a pointer, `getX(i)` returning an element, `get_x()`
  returning the vector -- and psir had only the first two, so `.psir.size()` and
  `.psir.empty()` had no public route. Added the missing
  `get_psir()`, completing the pattern rather than inventing an accessor for the
  test.

- `cal_kradial`, `cal_kradial_sbpool`, `cal_rradial_sbpool` and `plot` are
  private and are what four of the tests exist to exercise. These get
  `friend class NumericalOrbitalLmTest;`, next to the `friend class
  Numerical_Orbital;` the class already carries, plus four forwarding wrappers
  on the fixture -- a TEST_F body lives in a derived class and does not inherit
  friendship.

The substitution is uniform because the accessors return the member itself:
`get_psi()` yields `const std::vector<double>&`, so `.psi[i]`, `.psi.size()`,
`.psi.empty()` and bare `.psi` all keep working through it, and the scalar
getters return const references. Every site was rewritten mechanically and then
checked: no private member of the class is named in any TEST_F body any more.

No test expectation changed. Macro occurrences in this file go 1 -> 0; no
`#undef private` is added and no other file is touched.

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: Critsium-xy

source/source_basis/module_ao/orb_atomic_lm.h

@@ -20,6 +20,9 @@ using std::vector;
 class Numerical_Orbital_Lm
 {
 	friend class Numerical_Orbital;
+	/// the unit test drives cal_kradial(), cal_kradial_sbpool(),
+	/// cal_rradial_sbpool() and plot() directly
+	friend class NumericalOrbitalLmTest;
 
 	public:
 
@@ -139,6 +142,7 @@ class Numerical_Orbital_Lm
 	const std::vector<double>& get_psi() const { return psi; }
 	const double* getPsi_r() const { return ModuleBase::GlobalFunc::VECTOR_TO_PTR(psir); }
 	const double& getPsi_r(const int ir) const { return psir[ir]; }
+	const std::vector<double>& get_psir() const { return psir; }
 
 	const double* getPsif() const               { return ModuleBase::GlobalFunc::VECTOR_TO_PTR(psif); }
 	const double& getPsif(const int ik) const   { return psif[ik]; }