refactor: consolidate buildItemLink into game_utils.hpp

Three identical copies (game_handler.cpp, spell_handler.cpp,
quest_handler.cpp) plus two forward declarations (inventory_handler.cpp,
social_handler.cpp) replaced with a single inline definition in
game_utils.hpp. All affected files already include this header, so
quality color table changes now propagate from one source of truth.

include/game/game_utils.hpp

@@ -23,5 +23,25 @@ inline bool isPreWotlk() {
     return isClassicLikeExpansion() || isActiveExpansion("tbc");
 }
 
+// Shared item link formatter used by inventory, quest, spell, and social handlers.
+// Centralised here so quality color table changes propagate everywhere.
+inline std::string buildItemLink(uint32_t itemId, uint32_t quality, const std::string& name) {
+    static const char* kQualHex[] = {
+        "9d9d9d",  // 0 Poor
+        "ffffff",  // 1 Common
+        "1eff00",  // 2 Uncommon
+        "0070dd",  // 3 Rare
+        "a335ee",  // 4 Epic
+        "ff8000",  // 5 Legendary
+        "e6cc80",  // 6 Artifact
+        "e6cc80",  // 7 Heirloom
+    };
+    uint32_t qi = quality < 8 ? quality : 1u;
+    char buf[512];
+    snprintf(buf, sizeof(buf), "|cff%s|Hitem:%u:0:0:0:0:0:0:0:0|h[%s]|h|r",
+             kQualHex[qi], itemId, name.c_str());
+    return buf;
+}
+
 } // namespace game
 } // namespace wowee