feat: plinegen + SAB parsing for Solid3D/Region/Body

LwPolyline PLINEGEN=0 (DXF default): emit SegmentedLines with NaN
separators between vertex-to-vertex segments; wire_gpu resets
arc-length to 0 after each NaN so linetype pattern restarts per vertex.
PLINEGEN=1: existing Contour path unchanged (continuous pattern).
WireModel gains plinegen field propagated through tessellate pipeline.

Solid3D/Region/Body: call SabReader::read() when parse_sat() returns
None due to binary SAB format (DWG files / newer AutoCAD exports).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/modules/annotate/aligned_dim.rs

@@ -102,6 +102,7 @@ impl CadCommand for AlignedDimensionCommand {
             aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
         })
     }
 }
@@ -136,5 +137,6 @@ fn preview_aligned(p1: Vec3, p2: Vec3, dim_pt: Vec3) -> WireModel {
         aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
     }
 }

src/modules/annotate/angular_dim.rs

@@ -125,6 +125,7 @@ fn preview_wire(points: Vec<Vec3>) -> WireModel {
         aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
     }
 }
 

src/modules/annotate/diameter_dim.rs

@@ -101,5 +101,6 @@ fn preview_line(a: Vec3, b: Vec3) -> WireModel {
         aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
     }
 }

src/modules/annotate/dim_baseline.rs

@@ -143,6 +143,7 @@ impl CadCommand for DimBaselineCommand {
             aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
         })
     }
 }

src/modules/annotate/dim_continue.rs

@@ -140,6 +140,7 @@ impl CadCommand for DimContinueCommand {
             aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
         })
     }
 }

src/modules/annotate/dimjogline.rs

@@ -94,6 +94,7 @@ impl CadCommand for DimJogLineCommand {
             aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
         })
     }
 }

src/modules/annotate/dimtedit.rs

@@ -102,6 +102,7 @@ impl CadCommand for DimTeditCommand {
             aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
         })
     }
 

src/modules/annotate/leader_cmd.rs

@@ -202,6 +202,7 @@ fn preview_wire(pts: &[Vec3]) -> WireModel {
         aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
     }
 }
 

src/modules/annotate/linear_dim.rs

@@ -113,6 +113,7 @@ fn preview_wire(points: Vec<Vec3>) -> WireModel {
         aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
     }
 }
 

src/modules/annotate/mleader_cmd.rs

@@ -155,6 +155,7 @@ fn preview_wire(pts: &[Vec3]) -> WireModel {
         aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
     }
 }
 

src/modules/annotate/mleader_edit.rs

@@ -366,6 +366,7 @@ fn preview_wire(pts: &[Vec3]) -> WireModel {
         aci: 0,
         key_vertices: vec![],
         aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
     }
 }
 

src/modules/annotate/qdim.rs

@@ -99,6 +99,7 @@ impl CadCommand for QdimCommand {
             aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
         })
     }
 }

src/modules/annotate/radius_dim.rs

@@ -112,5 +112,6 @@ fn preview_wire(points: Vec<Vec3>) -> WireModel {
         aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
     }
 }

src/modules/annotate/table_cmd.rs

@@ -145,6 +145,7 @@ impl CadCommand for TableCommand {
                 aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
             })
         } else {
             None

src/modules/annotate/tolerance_cmd.rs

@@ -98,6 +98,7 @@ impl CadCommand for ToleranceCommand {
             aci: 0,
             key_vertices: vec![],
             aabb: WireModel::UNBOUNDED_AABB,
+            plinegen: true,
         })
     }
 }