fix: cleanup only old uploads, restore fav state on tinder undo

- #11: cleanup_old_uploads() skips dirs younger than 24h (safe during --reload)
- #12: tinderHistory stores wasFav snapshot; undo restores exact pre-swipe favorite state

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

index.html

@@ -1264,7 +1264,7 @@
       const photo = tinderQueue[tinderIndex];
       const card = el("tinder-card");
 
-      tinderHistory.push({ path: photo.path, decision: direction, index: tinderIndex });
+      tinderHistory.push({ path: photo.path, decision: direction, index: tinderIndex, wasFav: favoritePaths.has(photo.path) });
       tinderDecisions[photo.path] = direction === "right" || direction === "fav";
       if (direction === "fav") favoritePaths.add(photo.path);
 
@@ -1286,7 +1286,7 @@
       if (tinderSwiping || tinderHistory.length === 0) return;
       const last = tinderHistory.pop();
       delete tinderDecisions[last.path];
-      favoritePaths.delete(last.path);
+      if (last.wasFav) favoritePaths.add(last.path); else favoritePaths.delete(last.path);
       tinderIndex = last.index;
       const backAnim = last.decision === "left" ? "back-from-left"
                      : last.decision === "fav"  ? "back-from-top"