Add missing @file documentation blocks to 16 source files

Add Doxygen @file/@brief blocks to 13 modules that were missing them
(m_body_forces, m_igr, m_muscl, m_sim_helpers, m_surface_tension,
m_finite_differences, m_mpi_common, m_nvtx, m_delay_file_access,
m_phase_change, m_check_ib_patches, m_check_patches, m_simplex_noise)
and fix 3 files with malformed comment openers (m_chemistry used !!>
instead of !>, m_data_output and m_helper_basic started with !!
continuation markers instead of !> openers). All file list pages now
show descriptions for every entry.

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

Author: sbryngelson

src/common/m_chemistry.fpp

@@ -1,6 +1,6 @@
-!!>
+!>
 !! @file
-!! @brief  Contains module m_chemistry
+!! @brief Contains module m_chemistry
 !! @author Henry Le Berre <hberre3@gatech.edu>
 
 #:include 'macros.fpp'

src/common/m_delay_file_access.f90

@@ -1,3 +1,7 @@
+!>
+!! @file
+!! @brief Contains module m_delay_file_access
+
 module m_delay_file_access
     use m_precision_select
     implicit none

src/common/m_finite_differences.fpp

@@ -1,3 +1,7 @@
+!>
+!! @file
+!! @brief Contains module m_finite_differences
+
 #:include 'macros.fpp'
 
 module m_finite_differences

src/common/m_helper_basic.fpp

@@ -1,4 +1,4 @@
-
+!>
 !! @file
 !! @brief Contains module m_helper_basic
 

src/common/m_mpi_common.fpp

@@ -1,3 +1,7 @@
+!>
+!! @file
+!! @brief Contains module m_mpi_common
+
 #:include 'case.fpp'
 #:include 'macros.fpp'
 

src/common/m_nvtx.f90

@@ -1,3 +1,7 @@
+!>
+!! @file
+!! @brief Contains module m_nvtx
+
 module m_nvtx
 
     use iso_c_binding

src/common/m_phase_change.fpp

@@ -1,5 +1,7 @@
-!> energies (6-eqn to 4-eqn) equilibrium through an infinitely fast (algebraic)
-!> procedure.
+!>
+!! @file
+!! @brief Contains module m_phase_change
+
 #:include 'case.fpp'
 #:include 'macros.fpp'
 

src/pre_process/m_check_ib_patches.fpp

@@ -1,3 +1,7 @@
+!>
+!! @file
+!! @brief Contains module m_check_ib_patches
+
 !> @brief This module contains subroutines that read, and check consistency
 !!              of, the user provided inputs and data.
 

src/pre_process/m_check_patches.fpp

@@ -1,3 +1,7 @@
+!>
+!! @file
+!! @brief Contains module m_check_patches
+
 #:include 'macros.fpp'
 
 !> @brief This module contains subroutines that read, and check consistency

src/pre_process/m_simplex_noise.fpp

@@ -1,3 +1,7 @@
+!>
+!! @file
+!! @brief Contains module m_simplex_noise
+
 module m_simplex_noise
 
     use m_constants