Use explicit values when useImageAspectRatio doesn't know

It's not very good that you can't distingiush when we haven't loaded vs when we're certain. This shifts the burden of dealing with missing values to the caller.

src/view/com/util/images/AutoSizedImage.tsx

@@ -21,14 +21,19 @@ export function useImageAspectRatio({
   src: string
   dimensions: Dimensions | undefined
 }) {
-  const [raw, setAspectRatio] = React.useState<number>(
-    dimensions ? calc(dimensions) : 1,
+  const [raw, setAspectRatio] = React.useState(
+    dimensions ? calc(dimensions) : undefined,
   )
 
-  const ratio = 1 / 2 // max of 1:2 ratio in feeds
-  const constrained = Math.max(raw, ratio)
-  const max = Math.max(raw, 0.25) // max of 1:4 in thread
-  const isCropped = raw < constrained
+  let constrained: number | undefined
+  let max: number | undefined
+  let isCropped: boolean | undefined
+  if (raw !== undefined) {
+    const ratio = 1 / 2 // max of 1:2 ratio in feeds
+    constrained = Math.max(raw, ratio)
+    max = Math.max(raw, 0.25) // max of 1:4 in thread
+    isCropped = raw < constrained
+  }
 
   React.useEffect(() => {
     let aborted = false
@@ -215,14 +220,16 @@ export function AutoSizedImage({
           a.rounded_md,
           a.overflow_hidden,
           t.atoms.bg_contrast_25,
-          {aspectRatio: max},
+          {aspectRatio: max ?? 1},
         ]}>
         {contents}
       </Pressable>
     )
   } else {
     return (
-      <ConstrainedImage fullBleed={crop === 'square'} aspectRatio={constrained}>
+      <ConstrainedImage
+        fullBleed={crop === 'square'}
+        aspectRatio={constrained ?? 1}>
         <Pressable
           onPress={onPress}
           onLongPress={onLongPress}