feat: resolve spell \$d duration to real seconds from SpellDuration.dbc

Spell descriptions now substitute \$d with actual duration values:
  Before: "X damage over X sec"
  After:  "30 damage over 18 sec"

Implementation:
- DurationIndex field (40) added to all expansion Spell.dbc layouts
- SpellDuration.dbc loaded during cache build: maps index → base ms
- cleanSpellDescription substitutes \$d with resolved seconds/minutes
- getSpellDuration() accessor on GameHandler

Combined with \$s1/\$s2/\$s3 from the previous commit, most common
spell description templates are now fully resolved with real values.

Data/expansions/classic/dbc_layouts.json

@@ -168,6 +168,7 @@
     "AttributesEx": 6,
     "CastingTimeIndex": 15,
     "DispelType": 4,
+    "DurationIndex": 40,
     "EffectBasePoints0": 80,
     "EffectBasePoints1": 81,
     "EffectBasePoints2": 82,

Data/expansions/tbc/dbc_layouts.json

@@ -207,6 +207,7 @@
     "AttributesEx": 6,
     "CastingTimeIndex": 22,
     "DispelType": 3,
+    "DurationIndex": 40,
     "EffectBasePoints0": 80,
     "EffectBasePoints1": 81,
     "EffectBasePoints2": 82,

Data/expansions/turtle/dbc_layouts.json

@@ -201,6 +201,7 @@
     "AttributesEx": 6,
     "CastingTimeIndex": 15,
     "DispelType": 4,
+    "DurationIndex": 40,
     "EffectBasePoints0": 80,
     "EffectBasePoints1": 81,
     "EffectBasePoints2": 82,

Data/expansions/wotlk/dbc_layouts.json

@@ -223,6 +223,7 @@
     "AttributesEx": 5,
     "CastingTimeIndex": 47,
     "DispelType": 2,
+    "DurationIndex": 40,
     "EffectBasePoints0": 80,
     "EffectBasePoints1": 81,
     "EffectBasePoints2": 82,

include/game/game_handler.hpp

@@ -2245,6 +2245,7 @@ public:
     /// Returns the tooltip/description text from Spell.dbc (empty if unknown or has no text).
     const std::string& getSpellDescription(uint32_t spellId) const;
     const int32_t* getSpellEffectBasePoints(uint32_t spellId) const;
+    float getSpellDuration(uint32_t spellId) const;
     std::string getEnchantName(uint32_t enchantId) const;
     const std::string& getSkillLineName(uint32_t spellId) const;
     /// Returns the DispelType for a spell (0=none,1=magic,2=curse,3=disease,4=poison,5+=other)
@@ -3327,6 +3328,7 @@ private:
         std::string name; std::string rank; std::string description;
         uint32_t schoolMask = 0; uint8_t dispelType = 0; uint32_t attrEx = 0;
         int32_t effectBasePoints[3] = {0, 0, 0};
+        float durationSec = 0.0f; // resolved from DurationIndex → SpellDuration.dbc
     };
     std::unordered_map<uint32_t, SpellNameEntry> spellNameCache_;
     bool spellNameCacheLoaded_ = false;

src/addons/lua_engine.cpp

@@ -1627,7 +1627,7 @@ static int lua_GetSpellBookItemName(lua_State* L) {
 
 // GetSpellDescription(spellId) → description string
 // Clean spell description template variables for display
-static std::string cleanSpellDescription(const std::string& raw, const int32_t effectBase[3] = nullptr) {
+static std::string cleanSpellDescription(const std::string& raw, const int32_t effectBase[3] = nullptr, float durationSec = 0.0f) {
     if (raw.empty() || raw.find('$') == std::string::npos) return raw;
     std::string result;
     result.reserve(raw.size());
@@ -1657,8 +1657,15 @@ static std::string cleanSpellDescription(const std::string& raw, const int32_t e
                 i += 1;
                 while (i + 1 < raw.size() && raw[i + 1] >= '0' && raw[i + 1] <= '9') ++i;
             } else if (next == 'd' || next == 'D') {
-                // $d = duration — replace with "X sec"
-                result += "X sec";
+                // $d = duration
+                if (durationSec > 0.0f) {
+                    if (durationSec >= 60.0f)
+                        result += std::to_string(static_cast<int>(durationSec / 60.0f)) + " min";
+                    else
+                        result += std::to_string(static_cast<int>(durationSec)) + " sec";
+                } else {
+                    result += "X sec";
+                }
                 ++i;
                 while (i + 1 < raw.size() && raw[i + 1] >= '0' && raw[i + 1] <= '9') ++i;
             } else if (next == 'a' || next == 'A') {
@@ -1698,7 +1705,8 @@ static int lua_GetSpellDescription(lua_State* L) {
     uint32_t spellId = static_cast<uint32_t>(luaL_checknumber(L, 1));
     const std::string& desc = gh->getSpellDescription(spellId);
     const int32_t* ebp = gh->getSpellEffectBasePoints(spellId);
-    std::string cleaned = cleanSpellDescription(desc, ebp);
+    float dur = gh->getSpellDuration(spellId);
+    std::string cleaned = cleanSpellDescription(desc, ebp, dur);
     lua_pushstring(L, cleaned.c_str());
     return 1;
 }

src/game/game_handler.cpp

@@ -23200,9 +23200,33 @@ void GameHandler::loadSpellNameCache() {
                 if (f1 != 0xFFFFFFFF) entry.effectBasePoints[1] = static_cast<int32_t>(dbc->getUInt32(i, f1));
                 if (f2 != 0xFFFFFFFF) entry.effectBasePoints[2] = static_cast<int32_t>(dbc->getUInt32(i, f2));
             }
+            // Duration: read DurationIndex and resolve via SpellDuration.dbc later
+            if (spellL) {
+                uint32_t durF = spellL->field("DurationIndex");
+                if (durF != 0xFFFFFFFF)
+                    entry.durationSec = static_cast<float>(dbc->getUInt32(i, durF)); // store index temporarily
+            }
             spellNameCache_[id] = std::move(entry);
         }
     }
+    // Resolve DurationIndex → seconds via SpellDuration.dbc
+    auto durDbc = am->loadDBC("SpellDuration.dbc");
+    if (durDbc && durDbc->isLoaded()) {
+        std::unordered_map<uint32_t, float> durMap;
+        for (uint32_t di = 0; di < durDbc->getRecordCount(); ++di) {
+            uint32_t durId = durDbc->getUInt32(di, 0);
+            int32_t baseMs = static_cast<int32_t>(durDbc->getUInt32(di, 1));
+            if (baseMs > 0 && baseMs < 100000000) // filter out absurd values
+                durMap[durId] = baseMs / 1000.0f;
+        }
+        for (auto& [sid, entry] : spellNameCache_) {
+            uint32_t durIdx = static_cast<uint32_t>(entry.durationSec);
+            if (durIdx > 0) {
+                auto it = durMap.find(durIdx);
+                entry.durationSec = (it != durMap.end()) ? it->second : 0.0f;
+            }
+        }
+    }
     LOG_INFO("Trainer: Loaded ", spellNameCache_.size(), " spell names from Spell.dbc");
 }
 
@@ -23445,6 +23469,12 @@ const int32_t* GameHandler::getSpellEffectBasePoints(uint32_t spellId) const {
     return (it != spellNameCache_.end()) ? it->second.effectBasePoints : nullptr;
 }
 
+float GameHandler::getSpellDuration(uint32_t spellId) const {
+    const_cast<GameHandler*>(this)->loadSpellNameCache();
+    auto it = spellNameCache_.find(spellId);
+    return (it != spellNameCache_.end()) ? it->second.durationSec : 0.0f;
+}
+
 const std::string& GameHandler::getSpellName(uint32_t spellId) const {
     auto it = spellNameCache_.find(spellId);
     return (it != spellNameCache_.end()) ? it->second.name : EMPTY_STRING;