convenience features (#21)

core/include/ccm/services/PokemonSetCompletion.hpp

@@ -23,6 +23,7 @@ struct PokemonSetCompletionProgress {
     PokemonRegion region{PokemonRegion::West};
     std::string   setId;
     std::string   setName;
+    std::string   releaseDate;  // YYYY/MM/DD from owned cards; may be empty
     std::size_t   ownedUnique{0};
     std::size_t   total{0};
 
@@ -50,8 +51,9 @@ pokemonRegionsInCollection(const std::vector<PokemonCard>& collection,
                            const PokemonSetCatalog&        westCatalog,
                            const PokemonSetCatalog&        asiaCatalog);
 
-// Packs where the collection owns ≥1 matching card, ordered by setName then
-// region. When regionFilter is set, only that region's catalog/cards count.
+// Packs where the collection owns ≥1 matching card, ordered by releaseDate
+// then setName then region. When regionFilter is set, only that region's
+// catalog/cards count.
 [[nodiscard]] std::vector<PokemonSetCompletionProgress>
 computePokemonSetCompletion(const std::vector<PokemonCard>& collection,
                             const PokemonSetCatalog&        westCatalog,

core/include/ccm/util/SetNoNatural.hpp

@@ -0,0 +1,14 @@
+#pragma once
+
+// Natural (alphanumeric) ordering for collector / set numbers.
+// Digit runs compare as integers so "2" < "10" < "100"; non-digit runs use
+// ordinary string order (e.g. "SWSH001" < "SWSH002").
+
+#include <string_view>
+
+namespace ccm {
+
+// strcmp-style: <0 if a < b, 0 if equal (after natural + lex tie-break), >0 if a > b.
+[[nodiscard]] int compareSetNoNatural(std::string_view a, std::string_view b) noexcept;
+
+}  // namespace ccm