feat(render): double-single fills for the face3d pipeline

Table / PolyfaceMesh / greek-text / mleader-background fills go through
the face3d pipeline; their vertices were single f32 and quantized at UTM
scale. WireModel now carries a fill_tris_low residual (filled by the
tessellate Lines path), Face3DVertex gains position_low (location 3), and
face3d.wgsl reconstructs the eye-relative position from the pair. 3DFACE
quads built from key_vertices use a zero residual (no low source).

Co-Authored-By: Claude Opus 4.7 <[email protected]>

src/entities/dimension.rs

@@ -1172,6 +1172,7 @@ fn tessellate_dimension_inner(
                     plinegen: true,
                     vp_scissor: None,
                     fill_tris: vec![],
+                    fill_tris_low: Vec::new(),
                 });
             }
             if !ext2.is_empty() {
@@ -1192,6 +1193,7 @@ fn tessellate_dimension_inner(
                     plinegen: true,
                     vp_scissor: None,
                     fill_tris: vec![],
+                    fill_tris_low: Vec::new(),
                 });
             }
         } else {
@@ -1212,6 +1214,7 @@ fn tessellate_dimension_inner(
                 plinegen: true,
                 vp_scissor: None,
                 fill_tris: vec![],
+                fill_tris_low: Vec::new(),
             });
         }
     }
@@ -1233,6 +1236,7 @@ fn tessellate_dimension_inner(
         plinegen: true,
         vp_scissor: None,
         fill_tris: geom.arrow_fill,
+        fill_tris_low: Vec::new(),
     });
 
     // DIMTFILL: 0=none, 1=drawing background (mask), 2=DIMTFILLCLR.
@@ -1265,6 +1269,7 @@ fn tessellate_dimension_inner(
                     plinegen: true,
                     vp_scissor: None,
                     fill_tris: rect,
+                    fill_tris_low: Vec::new(),
                 });
             }
         }

src/entities/leader.rs

@@ -617,6 +617,7 @@ impl LeaderTess for Leader {
                 plinegen: true,
                 vp_scissor: None,
                 fill_tris: vec![],
+                fill_tris_low: Vec::new(),
             };
         }
 
@@ -716,6 +717,7 @@ impl LeaderTess for Leader {
             plinegen: true,
             vp_scissor: None,
             fill_tris,
+            fill_tris_low: Vec::new(),
         }
     }
 }

src/entities/multileader.rs

@@ -1309,6 +1309,7 @@ impl MultiLeaderTess for MultiLeader {
             plinegen: true,
             vp_scissor: None,
             fill_tris: arrow_fill,
+            fill_tris_low: Vec::new(),
         });
 
         // ── Block content ───────────────────────────────────────────────────────
@@ -1556,6 +1557,7 @@ impl MultiLeaderTess for MultiLeader {
                         plinegen: true,
                         vp_scissor: None,
                         fill_tris: vec![],
+                        fill_tris_low: Vec::new(),
                     });
                 }
             } else if lod_mode == 1 {
@@ -1597,6 +1599,7 @@ impl MultiLeaderTess for MultiLeader {
                         plinegen: true,
                         vp_scissor: None,
                         fill_tris: greek_tris,
+                        fill_tris_low: Vec::new(),
                     });
                 }
             } else {
@@ -1636,6 +1639,7 @@ impl MultiLeaderTess for MultiLeader {
                         plinegen: true,
                         vp_scissor: None,
                         fill_tris: vec![],
+                        fill_tris_low: Vec::new(),
                     });
                 }
             }
@@ -1694,6 +1698,7 @@ impl MultiLeaderTess for MultiLeader {
                         plinegen: true,
                         vp_scissor: None,
                         fill_tris,
+                        fill_tris_low: Vec::new(),
                     });
                 }
 
@@ -1723,6 +1728,7 @@ impl MultiLeaderTess for MultiLeader {
                         plinegen: true,
                         vp_scissor: None,
                         fill_tris: vec![],
+                        fill_tris_low: Vec::new(),
                     });
                 }
             }

src/entities/table.rs

@@ -716,6 +716,7 @@ pub fn tessellate_table(
                 plinegen: true,
                 vp_scissor: None,
                 fill_tris,
+                fill_tris_low: Vec::new(),
             }
         };