perf 5/5: startup on worker threads (first frame 82→49 ms), binary −1 MB

Cargo.toml

@@ -29,7 +29,10 @@ publish = false
 [workspace.dependencies]
 # Pinned exactly — validated by decision prototypes; see docs/decisions/.
 winit = "=0.30.13"
-wgpu = "=29.0.3"
+# No `gles`/`webgpu`: the renderer only ever requests `Backends::PRIMARY`
+# (Vulkan / Metal / DX12), so wgpu's GL backend (glow + EGL loader) was
+# compiled and linked in but unreachable, ~0.6 MB of the binary.
+wgpu = { version = "=29.0.3", default-features = false, features = ["std", "parking_lot", "dx12", "metal", "vulkan", "wgsl"] }
 naga = { version = "29", features = ["wgsl-in", "wgsl-out", "glsl-in"] }
 vte = "=0.15.0"
 cosmic-text = "=0.19.0"
@@ -106,6 +109,57 @@ lto = "thin"
 codegen-units = 1
 strip = "symbols"
 
+# Size-optimise cold, code-heavy dependencies: the Markdown block parsers
+# and layout engines (Mermaid, LaTeX maths, SVG tree building), the glTF /
+# OBJ loaders behind RGP, and petgraph (only the Wayland clipboard's MIME
+# sniffing uses it). Each runs once per block / asset / paste, never per
+# frame or per PTY byte, and rendering the demo Markdown document
+# (diagrams + maths) measured the same at "s" as at 3. Rasterisers
+# (tiny-skia, resvg), image codecs, regex engines, font parsing and
+# everything on the startup path, the config TOML parser included, stay
+# at opt-level 3.
+[profile.release.package.mermaid-svg]
+opt-level = "s"
+
+[profile.release.package.ratex-parser]
+opt-level = "s"
+
+[profile.release.package.ratex-layout]
+opt-level = "s"
+
+[profile.release.package.ratex-render]
+opt-level = "s"
+
+[profile.release.package.ratex-types]
+opt-level = "s"
+
+[profile.release.package.ratex-lexer]
+opt-level = "s"
+
+[profile.release.package.ratex-font]
+opt-level = "s"
+
+[profile.release.package.usvg]
+opt-level = "s"
+
+[profile.release.package.svgtypes]
+opt-level = "s"
+
+[profile.release.package.pulldown-cmark]
+opt-level = "s"
+
+[profile.release.package.gltf]
+opt-level = "s"
+
+[profile.release.package.gltf-json]
+opt-level = "s"
+
+[profile.release.package.tobj]
+opt-level = "s"
+
+[profile.release.package.petgraph]
+opt-level = "s"
+
 [profile.profiling]
 inherits = "release"
 debug = "line-tables-only"