perf(diff): Pierre diff optimizations (#419)

* perf: implement virtualized rendering for diff viewer

- Enables efficient rendering of large diffs by only rendering visible content
- Uses shared virtualizer cache to optimize memory across multiple diff viewers
- Configures virtual scrolling with 24px line height for consistent layout

* fix: improve diff viewer line selection and annotation rendering

* fix: normalize line ranges to prevent selection bugs

* chore: upgrade @opencode-ai/sdk to v1.1.65

packages/ui/src/components/views/DiffView.tsx

@@ -1082,6 +1082,8 @@ export const DiffView: React.FC = () => {
                     outerClassName="flex-1 min-h-0 h-full"
                     className="pr-2"
                     disableHorizontal
+                    data-diff-virtual-root
+                    data-diff-virtual-content
                 >
                     <div className="flex flex-col gap-3">
                         {changedFiles.map((file, index) => (
@@ -1144,7 +1146,7 @@ export const DiffView: React.FC = () => {
         }
 
         return (
-            <div className="flex flex-1 min-h-0 overflow-hidden px-3 py-3 relative">
+            <div className="flex flex-1 min-h-0 overflow-hidden px-3 py-3 relative" data-diff-virtual-root data-diff-virtual-content>
                 {renderSelectedDiffViewer()}
                 {isCurrentFileLoading && !hasCurrentDiff && (
                     <div className="absolute inset-0 flex items-center justify-center gap-2 text-sm text-muted-foreground">