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.

Cargo.toml

@@ -103,6 +103,11 @@ i18n-embed = { version = "0.16", features = ["desktop-requester"] }
 rayon = "1"
 open = "5"
 printpdf = { version = "0.9.1", default-features = false, features = ["images"] }
+# TrueType subsetting for searchable PDF text (same version printpdf itself
+# uses, so no new binary enters the lockfile). Same feature set as printpdf's
+# own allsorts use (pure-Rust flate backend) — the defaults would drag in the
+# libz-sys C dependency. Native-only like printpdf.
+allsorts = { version = "0.16", default-features = false, features = ["flate2_rust"] }
 ureq = { version = "3", default-features = false, features = ["rustls", "platform-verifier", "win-system-proxy"] }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]