rugnux: move RunAllPasses and the pass arbitration to RugnuxPasses.cpp

A verbatim move of RunAllPasses, RefinedPassIsWorse, ArmsHoldSameLattice and MeasuredCentreWins,
with the helpers only they read (MAX_CC_HALF_LOSS, SearchMergeCompletenessText,
PrimitiveCellVolume, SignalText, SameSetting) in the new file's anonymous namespace. The comment
describing RefinedPassIsWorse, which sat at the end of that anonymous namespace, now sits on the
function. TwinZoneVerdict stays behind for the scale/merge phase.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SVmAWnzCmRKAXVUCdc4iNi

rugnux/CMakeLists.txt

@@ -7,6 +7,7 @@ ADD_LIBRARY(JFJochRugnux STATIC
         RugnuxStills.cpp
         RugnuxCalibration.cpp
         RugnuxPreScan.cpp
+        RugnuxPasses.cpp
         RugnuxDefaults.cpp
         RugnuxDefaults.h
         Rugnux.h