feat(pipeline): add WLDS (Wowee Loading Screen) catalog

63rd open format — replaces LoadingScreens.dbc plus the
per-zone background-image tables. Defines the loading-screen
images shown when the client crosses into a new map /
instance, with optional level-bracket gating and expansion
gating (TBC art only shown if expansion installed).

When multiple screens match the player's current map + level
+ expansion, displayWeight selects randomly between them — a
zone with 3 weighted variants gets a different image roughly
proportional to weight.

4 expansion gates (Classic / TBC / WotLK / TurtleWoW),
isAnimated flag for screens with subtle animation,
isWideAspect flag for 16:9 raid intro art (vs 4:3 standard).

Cross-references with prior formats — mapId points at
WMS.map.mapId (which map triggers this loading screen);
mapId=0 is the catch-all sentinel for screens shown when
no map-specific screen matches.

CLI: --gen-lds (3 base screens — Elwynn level 1-30, Orgrimmar,
GenericFallback level 31-80 catch-all), --gen-lds-instances
(5 WotLK dungeon screens with mapId+expansion cross-refs:
Halls of Lightning/Stone, Utgarde Pinnacle, Violet Hold,
Old Kingdom), --gen-lds-raid (3 raid intro screens —
Naxxramas/Ulduar/ToC at isWideAspect=1 with weight=3),
--info-wlds, --validate-wlds with --json variants. Validator
catches id+name+texture required, expansion 0..3, level range
valid, weight=0 (in pool but never picked), and the practical
catch-all overlap warning when multiple mapId=0 screens share
overlapping level brackets (random pick becomes
non-deterministic).

Format graph: 62 → 63 binary formats. CLI flag count: 847
→ 854.

include/pipeline/wowee_loading_screens.hpp

@@ -0,0 +1,107 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace wowee {
+namespace pipeline {
+
+// Wowee Open Loading Screen catalog (.wlds) — novel
+// replacement for Blizzard's LoadingScreens.dbc plus the
+// per-zone background-image tables. Defines the loading
+// screen images shown when the client crosses into a new
+// map / instance, with optional level-bracket gating
+// (different art for early-zone vs raid-tier visits) and
+// expansion gating (TBC art only shown if expansion
+// installed).
+//
+// When multiple screens match the player's current map +
+// level + expansion, displayWeight selects randomly between
+// them — a zone with 3 weighted variants gets a different
+// image roughly proportional to weight.
+//
+// Cross-references with previously-added formats:
+//   WLDS.entry.mapId → WMS.map.mapId (which map triggers
+//                      this loading screen)
+//
+// Binary layout (little-endian):
+//   magic[4]            = "WLDS"
+//   version (uint32)    = current 1
+//   nameLen + name (catalog label)
+//   entryCount (uint32)
+//   entries (each):
+//     screenId (uint32)
+//     mapId (uint32)
+//     nameLen + name
+//     descLen + description
+//     texLen + texturePath
+//     iconLen + iconPath
+//     attribLen + attribution
+//     minLevel (uint16) / maxLevel (uint16)
+//     displayWeight (uint16) / pad[2]
+//     expansionRequired (uint8) / isAnimated (uint8) /
+//       isWideAspect (uint8) / pad[1]
+struct WoweeLoadingScreen {
+    enum ExpansionGate : uint8_t {
+        Classic   = 0,
+        TBC       = 1,
+        WotLK     = 2,
+        TurtleWoW = 3,
+    };
+
+    struct Entry {
+        uint32_t screenId = 0;
+        uint32_t mapId = 0;             // WMS cross-ref (0 = catch-all)
+        std::string name;
+        std::string description;
+        std::string texturePath;        // background image
+        std::string iconPath;           // small loading-bar icon
+        std::string attribution;        // artist credit
+        uint16_t minLevel = 1;
+        uint16_t maxLevel = 80;
+        uint16_t displayWeight = 1;     // weighted random pick
+        uint8_t expansionRequired = Classic;
+        uint8_t isAnimated = 0;
+        uint8_t isWideAspect = 0;       // 1 = 16:9, 0 = 4:3
+    };
+
+    std::string name;
+    std::vector<Entry> entries;
+
+    bool isValid() const { return !entries.empty(); }
+
+    const Entry* findById(uint32_t screenId) const;
+
+    static const char* expansionGateName(uint8_t e);
+};
+
+class WoweeLoadingScreenLoader {
+public:
+    static bool save(const WoweeLoadingScreen& cat,
+                     const std::string& basePath);
+    static WoweeLoadingScreen load(const std::string& basePath);
+    static bool exists(const std::string& basePath);
+
+    // Preset emitters used by --gen-lds* variants.
+    //
+    //   makeStarter   — 3 base screens (ElwynnForest,
+    //                    OrgrimmarLoading, GenericFallback
+    //                    with mapId=0 catch-all).
+    //   makeInstances — 5 WotLK dungeon loading screens
+    //                    (Halls of Lightning, Halls of
+    //                    Stone, Utgarde Pinnacle, Violet
+    //                    Hold, Old Kingdom) with proper
+    //                    mapId+expansion cross-refs.
+    //   makeRaidIntros — 3 raid loading screens (Naxxramas
+    //                     dragon-eye reveal, Ulduar Titan
+    //                     facility, ToC Argent Crusade) —
+    //                     marked isWideAspect for the wider
+    //                     16:9 raid intro art.
+    static WoweeLoadingScreen makeStarter(const std::string& catalogName);
+    static WoweeLoadingScreen makeInstances(const std::string& catalogName);
+    static WoweeLoadingScreen makeRaidIntros(const std::string& catalogName);
+};
+
+} // namespace pipeline
+} // namespace wowee