fix(widgets): restore the fork-local test/gltf/csg re-exports

The upstream sync at abd70f4 dropped three fork-local optional
dependencies from widgets/Cargo.toml and their re-exports from lib.rs.
They were fork additions, so the merge simply lost them.

The visible symptom in nigig-org was a resolver failure:

  package `nigig-pdf-makepad` depends on `makepad-widgets` with feature
  `test` but `makepad-widgets` does not have that feature.
  help: available features: default, serde
  failed to select a version for `makepad-widgets`

With no `test` feature on widgets 2.0.0, cargo falls back to the stale
old/widgets copy, which is 1.0.0 and offers only default and serde -
hence the misleading "available features" list.

libs/makepad_test itself was never removed; only the manifest entries and
the re-export were. Restores both, so makepad_widgets::makepad_test
resolves again.

widgets/Cargo.toml

@@ -28,6 +28,22 @@ ttf-parser = { path = "../libs/ttf-parser" }
 
 serde = { version = "1.0", optional = true, features = ["derive"] }
 
+# Public optional sibling crates, re-exported from lib.rs so an application
+# can depend on makepad-widgets as its sole Makepad source. These are
+# fork-local additions; an upstream sync dropped them at abd70f4, which
+# removed the `test` feature and broke every crate using makepad_test.
+[dependencies.makepad-gltf]
+path = "../libs/gltf"
+optional = true
+
+[dependencies.makepad-csg]
+path = "../libs/csg/csg"
+optional = true
+
+[dependencies.makepad-test]
+path = "../libs/makepad_test"
+optional = true
+
 [features]
 default = []
 
@@ -38,3 +54,6 @@ cef = ["dep:makepad-cef"]
 
 ## Enables certain public-facing types to derive serde serialization traits.
 serde = ["dep:serde", "makepad-draw/serde", "makepad-derive-widget/serde"]
+gltf = ["dep:makepad-gltf"]
+csg = ["dep:makepad-csg"]
+test = ["dep:makepad-test"]

widgets/src/lib.rs

@@ -9,6 +9,17 @@ pub use makepad_script::script_eval;
 pub use makepad_script::{ScriptValue, ScriptVm};
 
 pub use makepad_html;
+
+// Fork-local re-exports of the optional sibling crates, so an application
+// can depend on makepad-widgets alone. Lost in the upstream sync at
+// abd70f4; `makepad_test` in particular is imported as
+// `makepad_widgets::makepad_test` by every UI test suite in nigig-org.
+#[cfg(feature = "gltf")]
+pub use makepad_gltf;
+#[cfg(feature = "csg")]
+pub use makepad_csg;
+#[cfg(feature = "test")]
+pub use makepad_test;
 #[cfg(feature = "pdf")]
 pub use makepad_pdf_parse;