feat(block-editor): wire Rotation, Alignment and Flip parameter placement

Enable the existing palette rows and BPARAMETER choices. Rotation accepts a
center, picked or numeric radius, and picked or numeric default angle.
Alignment places a tangent direction from its base point. Flip places a
reflection line and state label, with native grip and state expressions.

Extend shared graph append/capacity checks for Flip's additional state node
while preserving existing subgraphs. Keep Polar/Rotation angle labels unique
in either placement order. Add editor graphics, extents and definition
reframing through the existing overlay/history/save paths.

This milestone implements native parameter placement and persistence.
Rotate/Flip action association, reference alignment/grip editing, parameter
property editing and parameter sets remain separate work.

Validation covers command and palette placement, cancellation, local/parent
undo, save/discard, native DWG/DXF objects, existing graph preservation and
the 17 research fixtures. Broader block/dock regressions and editor renders
are also checked.

src/app/command_driver/mod.rs

@@ -575,6 +575,9 @@ impl OpenCADStudio {
                     return task;
                 }
             }
+            result @ CmdResult::PlaceBlockOrientationParameter { .. } => {
+                return self.handle_place_block_orientation_parameter(result);
+            }
             result @ CmdResult::PlaceBlockDistanceParameter { .. } => {
                 return self.handle_place_block_distance_parameter(result);
             }