fix: new user scroll fix, add image lightbox

components/feed/new-users-strip.tsx

@@ -89,8 +89,13 @@ export function NewUsersStrip({ users }: { users: UserSummary[] }) {
         </div>
       </div>
 
-      {/* Bleed to the section edges (-mx-5) but keep a px-5 gutter so the
-          first/last tiles have breathing room as they scroll past. */}
+      {/* Bleed to the page edges, with a matching inner gutter so the first and
+          last tiles still have breathing room as they scroll past.
+          The negative margin MUST match the feed container's horizontal padding
+          (`main` is `px-4 sm:px-6`). It was `-mx-5` (20px) against a 16px
+          mobile padding, so the row hung 4px past each edge and gave the whole
+          document a horizontal scrollbar. Keep these three in lockstep with the
+          page padding if it ever changes. */}
       <div
         ref={scrollRef}
         onPointerDown={onPointerDown}
@@ -98,7 +103,7 @@ export function NewUsersStrip({ users }: { users: UserSummary[] }) {
         onPointerUp={onPointerUp}
         onPointerCancel={onPointerUp}
         onClickCapture={onClickCapture}
-        className="-mx-5 flex gap-3 overflow-x-auto px-5 py-1 snap-x scroll-px-5 cursor-grab select-none active:cursor-grabbing [scrollbar-width:none] [-ms-overflow-style:none] [&::-webkit-scrollbar]:hidden"
+        className="-mx-4 sm:-mx-6 flex gap-3 overflow-x-auto px-4 sm:px-6 py-1 snap-x scroll-px-4 sm:scroll-px-6 cursor-grab select-none active:cursor-grabbing [scrollbar-width:none] [-ms-overflow-style:none] [&::-webkit-scrollbar]:hidden"
       >
         {users.map((u) => (
           <Link