feat(pdf): searchable text layer with per-style subset font embedding

Real BT/Tj text objects ride alongside the vector outlines (Tr 3,
zero visual change): runs preserved at layout time, TTF styles embedded
as allsorts subsets with ToUnicode, width-matched Tm, clip-culled.
WireModel literals moved to ..Default::default() tails.

src/scene/text/complex_lt.rs

@@ -147,6 +147,7 @@ pub fn apply_along(
     // Embedded linetype text (LtSeg::Text) renders as SDF glyph quads collected
     // here; emitted as one extra text-carrying WireModel at the end.
     let mut text_verts: Vec<crate::scene::pipeline::text_gpu::TextVertex> = Vec::new();
+    let mut searchable: Vec<crate::scene::model::wire_model::SearchableTextRun> = Vec::new();
 
     let mut elem_idx: usize = 0;
     let mut elem_consumed: f32 = 0.0;
@@ -269,7 +270,7 @@ pub fn apply_along(
                     // SDF: glyph quads at the insert point (rotation baked in by
                     // layout_glyph_quads), collected for the text wire.
                     if let Ok(mut atlas) = crate::scene::text::sdf_atlas::text_atlas().lock() {
-                        let quads = crate::scene::text::glyph_quads::layout_glyph_quads(
+                        let (quads, pen_adv) = crate::scene::text::glyph_quads::layout_glyph_quads(
                             &mut atlas,
                             *tx_scale,
                             fwd_angle,
@@ -291,6 +292,28 @@ pub fn apply_along(
                             color,
                             0.0,
                         );
+                        {
+                            use crate::scene::model::wire_model::{
+                                clean_searchable_text, SearchableTextRun,
+                            };
+                            let visible = clean_searchable_text(&resolved);
+                            if !visible.is_empty() {
+                                searchable.push(SearchableTextRun {
+                                    text: visible,
+                                    origin: [
+                                        insert[0] as f64,
+                                        insert[1] as f64,
+                                        insert[2] as f64,
+                                    ],
+                                    height: *tx_scale,
+                                    rotation: fwd_angle,
+                                    color,
+                                    bold: false,
+                                    font: style.to_string(),
+                                    adv_width: pen_adv,
+                                });
+                            }
+                        }
                     }
 
                     elem_idx += 1;
@@ -342,7 +365,9 @@ pub fn apply_along(
             plinegen: true,
             fill_tris: vec![],
             fill_tris_low: Vec::new(),
-        })
+        
+            ..Default::default()
+})
         .collect();
 
     // Embedded linetype text (SDF): one extra wire carrying the glyph quads,
@@ -376,6 +401,7 @@ pub fn apply_along(
             dash_from_start: false,
             dash_align_end: None,
             text_verts,
+            searchable_text: searchable,
             name: name.to_string(),
             points: Vec::new(),
             points_low: Vec::new(),