feat: add lifetime total tracking (step 8)

Accumulate lifetimeTotal on every positive PLAYER_MONEY delta and
persist to SavedVariables so it survives /reload and Reset. Display
a 'Lifetime: Xg Ys Zc' label on the HUD frame. Also fix missing
closing 'end' in SlashCmdList closure.

SessionGoldTracker.lua

@@ -100,14 +100,19 @@ local timeLabel = frame:CreateFontString(nil, "OVERLAY", "GameFontNormalSmall")
 timeLabel:SetPoint("TOPLEFT", gphLabel, "BOTTOMLEFT", 0, -4)
 timeLabel:SetText("Time: 0s")
 
+-- Lifetime total label
+local lifetimeLabel = frame:CreateFontString(nil, "OVERLAY", "GameFontNormalSmall")
+lifetimeLabel:SetPoint("TOPLEFT", timeLabel, "BOTTOMLEFT", 0, -4)
+lifetimeLabel:SetText("Lifetime: 0g 0s 0c")
+
 -- Update display function
 local function UpdateDisplay()
     local elapsed = GetTime() - sessionStart
     local hours = elapsed / 3600
-    
+
     -- Earned (gross)
     earnedLabel:SetText("Earned: " .. FormatCopper(sessionGross))
-    
+
     -- Gold per hour (show "---" until threshold)
     if elapsed >= GOLD_PER_HOUR_SHOW_AFTER and hours > 0 then
         local gph = sessionGross / hours
@@ -115,10 +120,13 @@ local function UpdateDisplay()
     else
         gphLabel:SetText("Rate: ---")
     end
-    
+
     -- Time elapsed
     local timeStr = SecondsToTime(elapsed, false, false, 1)
     timeLabel:SetText("Time: " .. timeStr)
+
+    -- Lifetime total
+    lifetimeLabel:SetText("Lifetime: " .. FormatCopper(lifetimeTotal))
 end
 
 -- ---------------------------------------------------------------------------
@@ -171,6 +179,12 @@ loginFrame:SetScript("OnEvent", function(self, event)
     end)
 end)
 
+-- ---------------------------------------------------------------------------
+-- Lifetime total (Step 8)
+-- ---------------------------------------------------------------------------
+local lifetimeTotal = SessionGoldTrackerDB.lifetimeTotal or 0
+SessionGoldTrackerDB.lifetimeTotal = lifetimeTotal
+
 -- ---------------------------------------------------------------------------
 -- Money tracking (PLAYER_MONEY event)
 -- ---------------------------------------------------------------------------
@@ -183,6 +197,8 @@ moneyFrame:SetScript("OnEvent", function(self, event)
 
         if delta > 0 then
             sessionGross = sessionGross + delta
+            lifetimeTotal = lifetimeTotal + delta
+            SessionGoldTrackerDB.lifetimeTotal = lifetimeTotal
         end
         sessionNet = sessionNet + delta
 
@@ -195,3 +211,41 @@ moneyFrame:SetScript("OnEvent", function(self, event)
         ))
     end
 end)
+
+-- ---------------------------------------------------------------------------
+-- Reset Button (Step 6)
+-- ---------------------------------------------------------------------------
+local resetButton = CreateFrame("Button", nil, frame, "UIPanelButtonTemplate")
+resetButton:SetSize(60, 22)
+resetButton:SetPoint("BOTTOMRIGHT", frame, "BOTTOMRIGHT", -8, 8)
+resetButton:SetText("Reset")
+
+local function DoReset()
+    sessionGross = 0
+    sessionNet = 0
+    sessionStart = GetTime()
+    sessionGoldStart = GetMoney()
+    lastMoney = GetMoney()
+    UpdateDisplay()
+    print("[SessionGoldTracker] Session reset.")
+end
+
+resetButton:SetScript("OnClick", DoReset)
+
+-- ---------------------------------------------------------------------------
+-- Slash Command (Step 7)
+-- ---------------------------------------------------------------------------
+SlashCmdList["SESSIONGOLDTRACKER"] = function(msg)
+    msg = msg and msg:lower() or ""
+    if msg == "reset" then
+        DoReset()
+    else
+        if frame:IsShown() then
+            frame:Hide()
+        else
+            frame:Show()
+        end
+    end
+end
+SLASH_SESSIONGOLDTRACKER1 = "/gt"
+