refactor(ui): simplifies insertIdx, memoizes Set

Separates splice-shift correction from direction intent in insertIdx
computation. Moves Set construction from click handler into createMemo
so it derives once per prop change instead of per click.

Author: wgordon17

src/app/components/shared/RepoLockControls.tsx

@@ -9,6 +9,8 @@ interface RepoLockControlsProps {
 }
 
 export default function RepoLockControls(props: RepoLockControlsProps) {
+  const visibleSet = createMemo(() => new Set(props.visibleLockedRepos));
+
   const lockInfo = createMemo(() => {
     const isLocked = viewState.lockedRepos.indexOf(props.repoFullName) !== -1;
     const visIdx = props.visibleLockedRepos.indexOf(props.repoFullName);
@@ -53,7 +55,7 @@ export default function RepoLockControls(props: RepoLockControlsProps) {
         <Tooltip content={lockInfo().isFirst ? "Already at top of pinned list" : "Move up"}>
           <button
             class="btn btn-ghost btn-xs"
-            onClick={() => withFlipAnimation(() => moveLockedRepo(props.repoFullName, "up", new Set(props.visibleLockedRepos)))}
+            onClick={() => withFlipAnimation(() => moveLockedRepo(props.repoFullName, "up", visibleSet()))}
             disabled={lockInfo().isFirst}
             aria-label={`Move ${props.repoFullName} up`}
           >
@@ -66,7 +68,7 @@ export default function RepoLockControls(props: RepoLockControlsProps) {
         <Tooltip content={lockInfo().isLast ? "Already at bottom of pinned list" : "Move down"}>
           <button
             class="btn btn-ghost btn-xs"
-            onClick={() => withFlipAnimation(() => moveLockedRepo(props.repoFullName, "down", new Set(props.visibleLockedRepos)))}
+            onClick={() => withFlipAnimation(() => moveLockedRepo(props.repoFullName, "down", visibleSet()))}
             disabled={lockInfo().isLast}
             aria-label={`Move ${props.repoFullName} down`}
           >

src/app/stores/view.ts

@@ -372,10 +372,9 @@ export function moveLockedRepo(
 
     // Remove from old position and insert adjacent to target
     arr.splice(idx, 1);
-    // After removal, targetIdx shifts if source was before it
-    const insertIdx = direction === "up"
-      ? targetIdx - (idx < targetIdx ? 1 : 0)
-      : targetIdx - (idx < targetIdx ? 1 : 0) + 1;
+    // After removal, target index shifts down by 1 if source preceded it
+    const adjustedTarget = targetIdx - (idx < targetIdx ? 1 : 0);
+    const insertIdx = direction === "up" ? adjustedTarget : adjustedTarget + 1;
     arr.splice(insertIdx, 0, repoFullName);
   }));
 }