Update CHANGELOG.md

Author: ufechner7

CHANGELOG.md

@@ -1,17 +1,27 @@
 # Changelog
 
-## VortexStepMethod v3.3.4 2026-05-30
+## VortexStepMethod v3.3.4 2026-05-31
 
 ### Added
 - `PlotBackend`, `MakieBackend`, `ControlPlotsBackend`, and
   `set_plot_backend!` so applications can explicitly choose which plotting
   extension the backend-agnostic plotting API should use
+- `PythonCall` added as a weak dependency to support the `ControlPlots`
+  backend with PythonPlot
 
 ### Changed
 - backend-agnostic plotting wrappers now route through the active plotting
   backend, and each plotting extension initializes itself as the default only
   when no backend has been selected yet
 - relaxed `ControlPlots` compatibility to include both `0.2.5` and `0.3`
+- improved `bin/install` and `bin/install_controlplots` scripts
+
+### Fixed
+- corrected projection onto core radius in `velocity_3D_bound_vortex!` and
+  semi-infinite trailing vortex projection so that the radial direction is
+  always measured from the filament axis, not from the origin (#241)
+- fixed 0-based subplot indexing in `ControlPlotsExt` for PythonPlot
+  compatibility (`plot_distribution` no longer errors with PythonPlot backend)
 
 ## VortexStepMethod v3.3.3 2026-05-21