fix: Show commit nav for single-commit phases, remove early-exit guard

apps/web/src/components/review/CommitNav.tsx

@@ -16,21 +16,21 @@ export function CommitNav({
 }: CommitNavProps) {
   if (isLoading || commits.length === 0) return null;
 
-  // Don't show navigator for single-commit phases
-  if (commits.length === 1) return null;
-
   return (
     <div className="border-b border-border/50 bg-muted/20">
       <div className="flex items-center gap-0 px-4 overflow-x-auto">
-        {/* "All changes" pill */}
-        <CommitPill
-          label="All changes"
-          sublabel={`${commits.length} commits`}
-          isActive={selectedCommit === null}
-          onClick={() => onSelectCommit(null)}
-        />
-
-        <div className="w-px h-5 bg-border mx-1 shrink-0" />
+        {/* "All changes" pill — only when multiple commits */}
+        {commits.length > 1 && (
+          <>
+            <CommitPill
+              label="All changes"
+              sublabel={`${commits.length} commits`}
+              isActive={selectedCommit === null}
+              onClick={() => onSelectCommit(null)}
+            />
+            <div className="w-px h-5 bg-border mx-1 shrink-0" />
+          </>
+        )}
 
         {/* Individual commit pills - most recent first */}
         {commits.map((commit) => (