Geometry refinement: bound offline reprocessing by iterations, not the clock

The per-image refinement stopped on a wall-clock budget (40 ms, and 20 ms for
the rotation-only extra pass). Online that is exactly right - the budget is real
and an image that overruns it costs the acquisition. Offline it means the same
file refines to a different lattice depending on what else the machine was doing
at the time, which is not a property reprocessing should have.

Bound it by iteration count instead when the caller is offline. IndexAndRefine
takes the workflow as a constructor argument: the receiver asks for the
wall-clock bound, rugnux and the viewer get the reproducible one. 50 iterations
is Ceres' own default; the per-image problem converges well inside it, so it
bounds the pathological case rather than the normal one - measured on five
battery crystals, every number is unchanged from the timed version.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

image_analysis/IndexAndRefine.cpp

@@ -14,9 +14,18 @@
 #include "scale_merge/ReindexAmbiguity.h"
 #include "scale_merge/ScaleOnTheFly.h"
 
-IndexAndRefine::IndexAndRefine(const DiffractionExperiment &x, IndexerThreadPool *indexer, bool retain_outcomes)
+namespace {
+    // Iterations the offline geometry refinement is allowed, standing in for the 40 ms the online path
+    // spends. Ceres' own default is 50; the per-image problem is small and converges well inside that,
+    // so this bounds the pathological case rather than the normal one.
+    constexpr int OFFLINE_REFINE_ITERATIONS = 50;
+}
+
+IndexAndRefine::IndexAndRefine(const DiffractionExperiment &x, IndexerThreadPool *indexer,
+                               bool retain_outcomes, bool real_time)
     : index_ice_rings(x.GetIndexingSettings().GetIndexIceRings()),
       retain_outcomes_(retain_outcomes),
+      real_time(real_time),
       experiment(x),
       geom_(x.GetDiffractionGeometry()),
       indexer_(indexer),
@@ -258,7 +267,11 @@ void IndexAndRefine::RefineGeometryIfNeeded(DataMessage &msg, IndexAndRefine::In
         // enters the fit at the loose first tolerance is arbitrarily indexed noise. Weight every spot by
         // how strong it is for its resolution so those contribute without dragging the orientation.
         .weight_spots_by_confidence = true,
-        .max_time = 0.04 // 40 ms is max allowed time for the operation
+        // Online: 40 ms is the real budget per image, so the wall clock is the right bound even though
+        // it makes the answer depend on machine load. Offline: bound the same refinement by iterations
+        // instead, so reprocessing the same file twice gives the same lattice.
+        .max_time = 0.04,
+        .max_iterations = real_time ? 0 : OFFLINE_REFINE_ITERATIONS
     };
 
 
@@ -346,7 +359,8 @@ void IndexAndRefine::RefineGeometryIfNeeded(DataMessage &msg, IndexAndRefine::In
                 .refine_unit_cell = false,
                 .refine_rotation_axis = false,
                 .index_ice_rings = experiment.GetIndexingSettings().GetIndexIceRings(),
-                .max_time = 0.02
+                .max_time = 0.02,
+                .max_iterations = real_time ? 0 : OFFLINE_REFINE_ITERATIONS / 2
             };
             XtalOptimizerRotationOnly(data_extra, msg.spots, 0.1);
             el = data_extra.latt;