test(v0): use component-scoped generated APIs

Drop the v0 example's global export opt-in and update tests to use component-scoped slots and forms, matching the checked public API path.

req: component/003

req: build/001

examples/v0/build.rs

@@ -1,3 +1,3 @@
 fn main() {
-    slhx_build::app().global_exports(true).run().unwrap();
+    slhx_build::app().run().unwrap();
 }