fix: resolve ByBlock color, linetype, and lineweight through INSERT chain

Block sub-entities with ByBlock color now inherit their INSERT's resolved
color instead of rendering as the default white. ByBlock linetype inherits
the INSERT's linetype pattern, and ByBlock lineweight inherits the INSERT's
effective line weight.

Implemented via render_style_for_block_sub(), called in tessellate_entity()
when expanding INSERT exploded entities.

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

src/scene/mod.rs

@@ -2630,6 +2630,9 @@ fn tessellate_entity(
 
     if let EntityType::Insert(ins) = e {
         let is_mirrored = ins.x_scale() * ins.y_scale() < 0.0;
+        // Resolve the INSERT's own style so ByBlock sub-entities can inherit it.
+        let (ins_color, ins_pat_len, ins_pat, ins_lw_px, _) =
+            render::render_style_for(document, e);
         return ins
             .explode_from_document(document)
             .iter()
@@ -2638,7 +2641,10 @@ fn tessellate_entity(
             .map(|sub| crate::modules::home::modify::explode::fix_mirrored_arc(sub, is_mirrored))
             .flat_map(|sub| {
                 let (sub_color, sub_pattern_length, sub_pattern, sub_line_weight_px, sub_aci) =
-                    render::render_style_for(document, &sub);
+                    render::render_style_for_block_sub(
+                        document, &sub,
+                        ins_color, ins_pat_len, ins_pat, ins_lw_px,
+                    );
                 let sub_aabb = entity_aabb(&sub);
                 let mut wire = tessellate::tessellate(
                     document,