fix(metadata): drop unneeded scrollbar on MetadataText values (#765)

Each MetadataText value rendered with `overflow-y: scroll`, which forces
a scrollbar even when no max-height is set. Chromium-based Edge on
Windows draws classic scrollbar arrow buttons on every forced scrollbar,
producing visible up/down chevrons next to single-line values like the
publisher, bookmark progress, and date. Other Chromium browsers don't
draw the arrows, so this only manifested on Edge.

Switch to `overflow-y: auto` so the scrollbar only appears for the two
fields that actually need it (Summary and Review, which have
`max-height: 100`). The `isOverflow` measurement still works since it
compares `clientHeight` to `scrollHeight`, which is identical under
`auto`.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: ajslater

frontend/src/components/metadata/metadata-text.vue

@@ -234,7 +234,7 @@ export default {
 }
 
 .textValue {
-  overflow-y: scroll;
+  overflow-y: auto;
 }
 
 .expandButton {