docs: the stills rocking-curve datasets in the _process.h5 master

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015CeEGgpKdfkCTJb3YNMJcu
(cherry picked from commit 1195b9be6e0ca66774774f6de4867180b7bd0a47)

docs/HDF5.md

@@ -394,6 +394,9 @@ variants.
 | `iceRingScoreMean` | ratio | mean `iceRingScore` over the run — the single "how icy was this dataset" number (1 = no ice) |
 | `indexedLatticeCount` | | per-image lattice count summary (master). *Note: data files use `indexingLatticeCount`; readers accept either.* |
 | `reindexMatrix` | | change of basis from the setting the per-image data are in to the setting of `/entry/sample/unit_cell` (`[9]`, `int32`, flattened 3×3, row major) — see below |
+| `stillsRockingWidthFormula` | 1/Å, rad, relative | stills: the run's rocking width σ² = γ₀² + (γₑ d\*)² + (σ_bw λ d\*²/2)², as `[γ₀, γₑ, σ_bw]`; offline (Rugnux) only |
+| `stillsRadialScale` | | stills: the scale of the reciprocal lattice the rocking curve is centred on |
+| `stillsRockingWidthTableDstar`, `stillsRockingWidthTable` | 1/Å | stills: the rocking width σ measured against d\*, which the partialities use (held beyond the first and last entry; the formula above is what the prediction window uses); `--mode scale` merges with formula and table instead of measuring another |
 
 **Reindex matrix.** The per-image `h`, `k`, `l` and `latticeIndexed` are written as each image is
 processed, in the setting that image was *indexed* in. The space group is only settled afterwards, by