Stop forced layout reads in the bottom-anchored scroll hot path - #2280

Actions cache usage is 11.10 GB of 10.00 GB (111%) across 31 entries. GitHub evicts least-recently-used entries without reporting it, so caches are about to start missing. Run `gh cache list --limit 100 --json key,sizeInBytes` to find the job writing oversized entries; a job on a Blacksmith Linux runner should not appear here at all.

src/components/secondary-panel/BrowserTabContent.tsx:474:16: Cannot access refs during render

src/components/secondary-panel/BrowserTabContent.tsx:922:7: Calling setState synchronously within an effect can trigger cascading renders

src/components/secondary-panel/BrowserTabContent.tsx:785:5: Calling setState synchronously within an effect can trigger cascading renders

src/components/secondary-panel/BrowserTabContent.tsx:597:5: Calling setState synchronously within an effect can trigger cascading renders

src/components/secondary-panel/ThreadSecondaryPanel.stories.tsx:421:5: Calling setState synchronously within an effect can trigger cascading renders

src/components/secondary-panel/ThreadSecondaryPanel.stories.tsx:132:5: Calling setState synchronously within an effect can trigger cascading renders

src/components/thread/timeline/useScrollToSearchedMessage.ts:206:17: Cannot access refs during render

src/components/thread/timeline/conversation-message-overflow.tsx:110:7: Calling setState synchronously within an effect can trigger cascading renders

src/components/plugin/PluginComposerActions.stories.tsx:239:11: Cannot access refs during render