How metrics are computed at sura level
- M1 — Total letter count for the sura.
- M2 — Total word count for the sura.
- M3 — Total abjad sum for the sura.
- M4 — Verse-order concatenation of each verse's M1 value.
- M5 — Verse-order concatenation of each verse's M2 value.
- M6 — Reverse-order concatenation of each verse's M1 value.
- M7 — Reverse-order concatenation of each verse's M2 value.
Data source: phase4/grand_sura_lock_summary.json — one file, all 10 mushafs.
Each value includes its digit length and mod-19 residue.