fix(polyline): render fill mode boundaries

Use kernel-produced band outlines when FILLMODE is off. Preserve centerline linetype stations through inserts, clipping, projection, and PDF export.

src/scene/convert/tess.rs

@@ -750,6 +750,7 @@ fn tessellate_entity_inner(
         return vec![WireModel {
             point_marker: None,
             taper_widths: Vec::new(),
+            pattern_stations: Vec::new(),
             world_width: 0.0,
             depth_override: None,
             display_visible: true,
@@ -1110,6 +1111,7 @@ fn tessellate_entity_inner(
         let marker = WireModel {
             point_marker: None,
             taper_widths: Vec::new(),
+            pattern_stations: Vec::new(),
             world_width: 0.0,
             depth_override: None,
             display_visible: true,
@@ -1508,6 +1510,7 @@ fn lod_stub_wire(
     WireModel {
         point_marker: None,
         taper_widths: Vec::new(),
+        pattern_stations: Vec::new(),
         world_width: 0.0,
         depth_override: None,
         display_visible: true,
@@ -1602,6 +1605,7 @@ fn lod_stub_wire_3d(
     WireModel {
         point_marker: None,
         taper_widths: Vec::new(),
+        pattern_stations: Vec::new(),
         world_width: 0.0,
         depth_override: None,
         display_visible: true,