fix(pdf): avoid closing renderer via delegated read in DisposableEffect

DisposableEffect(handleState) captured handleState as a property
delegate, so onDispose read the *current* delegated value at dispose
time. When the async load transitioned handleState from null to the
new handle, the previous DisposableEffect(null) was forgotten and its
onDispose fired — reading the freshly-created handle via the delegate
and closing it immediately. That left the dialog stuck on the loading
spinner (page renders bailed out due to the closed flag) and double-
closed the renderer on dismiss.

Capture the handle as a local val before DisposableEffect so the
lambda closes the specific handle that was current at effect creation.

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/components/pdf/PdfViewerDialog.kt

@@ -161,9 +161,15 @@ private fun PdfViewerContent(
             }
     }
 
-    DisposableEffect(handleState) {
+    // Capture the handle as a local val so the onDispose lambda closes *this* handle,
+    // not whatever the delegated property reads at dispose time. Without this, the
+    // DisposableEffect keyed on handleState runs its onDispose when handleState
+    // transitions from null -> handle, and `handleState?.close()` reads the new handle
+    // and closes it right after it was created.
+    val handleForDispose = handleState
+    DisposableEffect(handleForDispose) {
         onDispose {
-            handleState?.close()
+            handleForDispose?.close()
         }
     }