feat(build): emit checked component refs

Generate ComponentRef constants for component-scoped APIs, include global component refs only when global_exports(true) is enabled, and document/use the checked component token.

req: component/003

slhx-core/src/lib.rs

@@ -186,6 +186,35 @@ impl core::fmt::Display for CssClass {
     }
 }
 
+/// A generated, checked component token.
+/// req: component/003
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
+pub struct ComponentRef {
+    name: &'static str,
+}
+
+impl ComponentRef {
+    pub const fn new(name: &'static str) -> Self {
+        Self { name }
+    }
+
+    pub const fn as_str(self) -> &'static str {
+        self.name
+    }
+}
+
+impl AsRef<str> for ComponentRef {
+    fn as_ref(&self) -> &str {
+        self.name
+    }
+}
+
+impl core::fmt::Display for ComponentRef {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        f.write_str(self.name)
+    }
+}
+
 /// A generated, checked event token.
 /// req: codegen/006
 #[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]