simplify reactive context and expose less signal internals

packages/signals/src/global/memo.rs

@@ -66,8 +66,8 @@ impl<T: PartialEq + 'static> Readable<T> for GlobalMemo<T> {
     }
 
     #[track_caller]
-    fn read(&self) -> Self::Ref<T> {
-        self.signal().read()
+    fn try_read(&self) -> Result<Self::Ref<T>, generational_box::BorrowError> {
+        self.signal().try_read()
     }
 
     #[track_caller]

packages/signals/src/global/signal.rs

@@ -89,8 +89,8 @@ impl<T: 'static> Readable<T> for GlobalSignal<T> {
     }
 
     #[track_caller]
-    fn read(&self) -> Self::Ref<T> {
-        self.signal().read()
+    fn try_read(&self) -> Result<Self::Ref<T>, generational_box::BorrowError> {
+        self.signal().try_read()
     }
 
     #[track_caller]