refactor(text): per-entity SDF text — all text kinds, selection/hover highlight

Rearchitect SDF text from a document-wide collector to per-entity
production during tessellation, so each entity owns its glyph quads and
composite/nested text is covered for free (no re-explosion, no per-frame
document walk).

- WireModel gains `text_verts`: glyph quads ride on the wire, so they are
  cached by the tess memo, cloned on hit, and transformed by the block
  expand loop exactly like `points`.
- Text arm (tessellate.rs) builds the quads when SDF is on and suppresses
  the strokes; render gathers text_verts from the viewport wire set
  (`gather_text_verts`, cached on wire content id) — the old collector is
  removed. Covers model, dimension, table, block-internal and paper-sheet
  text uniformly.
- MLEADER text (lays out via layout_mtext, not the Text arm) gets its own
  SDF branch driven by the per-run GlyphRun.
- Pick box comes from the rendered glyph quads (true text extent), not
  entity_aabb which mis-places the box for MTEXT; composite paths no longer
  clobber the empty text wire's tight AABB (dim pick box hugs the text).
- Selection / hover highlight via a text-highlight overlay (upload_text_
  highlight, keyed on selection_generation) mirroring the selected-wire
  xray overlay; base glyphs stay neutral so a deselect leaves no stale tint.
- Debug: env OCS_TEXT_BOX draws each run's glyph-bounds rectangle.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

src/modules/draw/draw/attdef.rs

@@ -160,6 +160,7 @@ impl CadCommand for AttdefCommand {
         // Show a small cross at the insertion point.
         let d = 0.15_f32;
         Some(WireModel {
+            text_verts: Vec::new(),
             name: "attdef_preview".into(),
             points: vec![
                 [pt.x - d, pt.y, pt.z],

src/modules/draw/draw/mline.rs

@@ -131,6 +131,7 @@ impl CadCommand for MlineCommand {
         let mut pts: Vec<[f32; 3]> = self.points.iter().map(|p| [p.x, p.y, p.z]).collect();
         pts.push([pt.x, pt.y, pt.z]);
         Some(WireModel {
+            text_verts: Vec::new(),
             name: "mline_preview".into(),
             points: pts,
             points_low: Vec::new(),

src/modules/draw/draw/raster_image.rs

@@ -108,6 +108,7 @@ impl CadCommand for ImageCommand {
         let p3 = [origin.x, origin.y + world_height, origin.z];
 
         Some(WireModel {
+            text_verts: Vec::new(),
             name: "image_preview".into(),
             points: vec![p0, p1, p2, p3, p0],
             points_low: Vec::new(),

src/modules/draw/draw/ray.rs

@@ -74,6 +74,7 @@ impl CadCommand for RayCommand {
         let dir = (pt - base).normalize_or_zero();
         let far = base + dir * DISPLAY_EXTENT;
         Some(WireModel {
+            text_verts: Vec::new(),
             name: "ray_preview".into(),
             points: vec![[base.x, base.y, base.z], [far.x, far.y, far.z]],
             points_low: Vec::new(),
@@ -154,6 +155,7 @@ impl CadCommand for XLineCommand {
         let far_pos = base + dir * DISPLAY_EXTENT;
         let far_neg = base - dir * DISPLAY_EXTENT;
         Some(WireModel {
+            text_verts: Vec::new(),
             name: "xline_preview".into(),
             points: vec![
                 [far_neg.x, far_neg.y, far_neg.z],

src/modules/draw/draw/revcloud.rs

@@ -80,6 +80,7 @@ impl CadCommand for RevCloudCommand {
         preview_pts.push([pt.x, pt.y, pt.z]);
         preview_pts.push([self.points[0].x, self.points[0].y, self.points[0].z]);
         Some(WireModel {
+            text_verts: Vec::new(),
             name: "revcloud_preview".into(),
             points: preview_pts,
             points_low: Vec::new(),

src/modules/draw/draw/wipeout.rs

@@ -114,6 +114,7 @@ impl CadCommand for WipeoutCommand {
                 let min = p1.min(pt);
                 let max = p1.max(pt);
                 Some(WireModel {
+            text_verts: Vec::new(),
                     name: "wipeout_preview".into(),
                     points: vec![
                         [min.x, min.y, min.z],
@@ -148,6 +149,7 @@ impl CadCommand for WipeoutCommand {
                 pts.push([pt.x, pt.y, pt.z]);
                 pts.push([self.poly_pts[0].x, self.poly_pts[0].y, self.poly_pts[0].z]);
                 Some(WireModel {
+            text_verts: Vec::new(),
                     name: "wipeout_poly_preview".into(),
                     points: pts,
                     points_low: Vec::new(),

src/modules/draw/inquiry/area.rs

@@ -69,6 +69,7 @@ impl CadCommand for AreaCommand {
         pts.push(f(pt));
         pts.push(f(self.points[0]));
         Some(WireModel {
+            text_verts: Vec::new(),
             name: "area_preview".into(),
             points: pts,
             points_low: Vec::new(),

src/modules/draw/inquiry/dist.rs

@@ -63,6 +63,7 @@ impl CadCommand for DistCommand {
         let p1 = self.first?;
         // The preview wire is purely visual, so f32 vertices are fine here.
         Some(WireModel {
+            text_verts: Vec::new(),
             name: "dist_preview".into(),
             points: vec![
                 [p1.x as f32, p1.y as f32, p1.z as f32],

src/modules/draw/inquiry/measuregeom.rs

@@ -67,6 +67,7 @@ impl MeasureGeomCommand {
     /// Build a cyan preview wire connecting the picked points and the cursor.
     fn preview_wire(name: &str, pts: Vec<[f32; 3]>) -> WireModel {
         WireModel {
+            text_verts: Vec::new(),
             name: name.to_string(),
             points: pts,
             points_low: Vec::new(),