rotation indexer: fix sub-range crash, explicit angle, settings + guards

Running rotation indexing on a sub-range (e.g. images 60-120) segfaulted: the
first pass passed the *global* image number to RotationIndexer::ProcessImage,
which indexes v_ (sized to the run's image count) -> out-of-bounds write.

- ProcessImage now takes an explicit mid-exposure angle (optional; falls back to
  the goniometer at the image index), so the indexer no longer assumes its slot
  index equals the goniometer image index. IndexAndRefine supplies it via
  RotationAngle(), matching the angle used for prediction. Added a bounds guard in
  ProcessImage so a bad index can never corrupt memory.
- JFJochProcess feeds the rotation indexer the local ordinal (not the global
  index), and shifts the goniometer (start += start_image*incr, incr *= stride,
  per-image wedge preserved) so local index i maps to the angle of original image
  start+i*stride - fixing rotation angles for the whole sub-range pipeline
  (prediction, refinement, output), not just the indexer.
- Expose "Rotation images" (number used for the first pass) in the job dialog,
  enabled when rotation indexing is on. (Count > available is already clamped by
  select_equally_spaced_image_ordinals.)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

image_analysis/IndexAndRefine.cpp

@@ -28,9 +28,16 @@ IndexAndRefine::IndexAndRefine(const DiffractionExperiment &x, IndexerThreadPool
     unit_cells.resize(x.GetImageNum());
 }
 
+std::optional<float> IndexAndRefine::RotationAngle(int64_t image) const {
+    // Mid-exposure rotation angle for image index `image`, matching the angle used for prediction.
+    if (const auto g = experiment.GetGoniometer())
+        return g->GetAngle_deg(static_cast<float>(image)) + g->GetWedge_deg() / 2.0f;
+    return std::nullopt;
+}
+
 void IndexAndRefine::AddImageToRotationIndexer(DataMessage &msg) {
     if (rotation_indexer)
-        rotation_indexer->ProcessImage(msg.number, msg.spots);
+        rotation_indexer->ProcessImage(msg.number, msg.spots, RotationAngle(msg.number));
 }
 
 IndexAndRefine::IndexingOutcome IndexAndRefine::DetermineLatticeAndSymmetryRotation(DataMessage &msg) {
@@ -44,7 +51,7 @@ IndexAndRefine::IndexingOutcome IndexAndRefine::DetermineLatticeAndSymmetryRotat
     if (!result.has_value()) {
         auto rot_cnt = rotation_indexer_counter.Process(msg.number);
         if (rot_cnt.first)
-            rotation_indexer->ProcessImage(msg.number, msg.spots);
+            rotation_indexer->ProcessImage(msg.number, msg.spots, RotationAngle(msg.number));
         if (rot_cnt.second)
             rotation_indexer->RunIndexing();
         result = rotation_indexer->GetLattice();