refactor(text): SDF for all text kinds; remove the legacy stroke text path

SDF is the only text renderer now — the stroke path and its LOD ladder are
gone, and the remaining text kinds render as SDF glyph quads too.

- ATTDEF / ATTRIB: carry a GlyphRun so single-line attribute text renders as
  SDF (multi-line already did via layout_mtext). Tolerance / complex-linetype
  text already SDF.
- Remove `sdf_text_enabled()` (the OCS_TEXT_SDF flag / kill switch) and take
  the SDF path unconditionally everywhere: tessellate Text arm (per-group by
  GlyphRun presence), hit_test fallbacks, render gather, complex_lt, table,
  mleader.
- Delete the text LOD ladder: tess.rs baseline/greek block and the
  block_cache greek/baseline path (emit_greeked_text / emit_text_baseline),
  plus the now-dead helpers text_baseline_points / text_greek_obb_tris /
  text_obb_corners_native / mtext_line_count and the LocalWire
  text_height_local / text_obb_local fields. All text is crisp at every zoom;
  text entities are exempt from the sub-pixel stub cull.
- Fix a latent bug: block-internal SDF text was culled because its LocalWire
  aabb_local was [0,0,0,0] (no points) — fold the glyph-quad extent into
  aabb_local and exempt text_verts-carrying wires from the sub-pixel cull.
- Clear the pre-existing dead-code warnings (TextPlacement.elevation, TabKind,
  MTextRunKind::Tab).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/entities/attribute.rs

@@ -11,7 +11,7 @@ use crate::entities::text_support::{
     MTextRenderOpts, MTextVAnchor, ResolvedTextStyle,
 };
 use crate::entities::traits::{Grippable, PropertyEditable, Transformable, TruckConvertible};
-use crate::scene::convert::acad_to_truck::{TextStroke, TruckEntity, TruckObject};
+use crate::scene::convert::acad_to_truck::{GlyphRun, TextStroke, TruckEntity, TruckObject};
 use crate::scene::model::object::{GripApply, GripDef, PropSection, PropValue, Property};
 use crate::scene::model::wire_model::SnapHint;
 use crate::scene::text::lff;
@@ -295,7 +295,18 @@ fn build_attr_truck(input: AttrTextInputs<'_>, document: &acadrust::CadDocument)
             origin,
             color: None,
             fill_tris,
-            run: None,
+            // Carry a GlyphRun so the attribute renders as SDF glyph quads
+            // (same as TEXT); the strokes above are the historical fallback and
+            // are suppressed by the per-group SDF path.
+            run: Some(GlyphRun {
+                text: encoded,
+                font: resolved.font_name.clone(),
+                height: input.height as f32,
+                rotation,
+                width_factor,
+                oblique: oblique_angle,
+                tracking: 1.0,
+            }),
         });
     }
     let _ = input.line_count; // round-trip only — recomputed above