Fix mixed-precision literals in hyper_cleaning psi initialization

Replace `1d-2` (hard double precision) and bare `2.0`/`0.05` (default
real) with `_wp`-suffixed literals so the Gaussian initialization is
consistent with the working precision across single and double builds.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: sbryngelson

src/pre_process/m_start_up.fpp

@@ -791,9 +791,9 @@ contains
                 do k = 0, n
                     do j = 0, m
                         if (p > 0) then
-                            q_cons_vf(psi_idx)%sf(j, k, l) = 1d-2*exp(-(x_cc(j)**2 + y_cc(k)**2 + z_cc(l)**2)/(2.0*0.05**2))
+                            q_cons_vf(psi_idx)%sf(j, k, l) = 1.0e-2_wp*exp(-(x_cc(j)**2 + y_cc(k)**2 + z_cc(l)**2)/(2.0_wp*0.05_wp**2))
                         else
-                            q_cons_vf(psi_idx)%sf(j, k, l) = 1d-2*exp(-(x_cc(j)**2 + y_cc(k)**2)/(2.0*0.05**2))
+                            q_cons_vf(psi_idx)%sf(j, k, l) = 1.0e-2_wp*exp(-(x_cc(j)**2 + y_cc(k)**2)/(2.0_wp*0.05_wp**2))
                         end if
                         q_prim_vf(psi_idx)%sf(j, k, l) = q_cons_vf(psi_idx)%sf(j, k, l)
                     end do