Multi-modal neuroimaging pipelines for data preprocessing

Add autoptX/rfMRI IDPs, pipeline success sentinels, and bug fixes

New features:

• Add autoptX tractography IDP extraction (243 IDPs: 27 tracts x 9 metrics)
• Add rfMRI IDP extraction script and headers
• Add melodic IC templates (25 and 100 components)
• Add XTRACT tractography support in dMRI pipeline
• Write TSV header row before subject loop in IDP extraction

Bug fixes:

• Fix dtifit mask: use nodif_brain_mask (binary) not nodif_brain (intensity)
• Fix DTI shell selection: use only highest b-value shell
• Fix GM parcellation: read volume_mm3 column not nvoxels
• Fix FIRST volumes: output in mm3 using voxel dimensions from fslval
• Fix FreeSurfer 7 thalamus label renaming (Left/Right-Thalamus-Proper)
• Fix brc_FS_get_IDPs.py: read values not headers from data_dict
• Fix dc precision in noise ratio calculation
• Fix integer comparison in brc_IDP_diff_TBSS.sh
• Fix b-value float comparison in Pipeline_NODDI_Watson.sh
• Fix safe variable defaults in Pipeline_NODDI_Watson.sh
• Fix sed multiple-space collapse pattern in idp_extract_part_1.sh
• Fix mkdir -p for bedpostxFolder

Robustness:

• Add .DIFF_SUCCESS, .FMRI_SUCCESS, .STRUCT_SUCCESS pipeline sentinels
• Add result="" initialisation in brc_IDP_all_align_to_T1.sh
• Remove dead HCP-only code (run_eddy_qunex.sh)
• Add IDP_list.txt entries for 243 autoptX IDPs (indices 888-1130)