player: drop talent-side modCastingTime fudge from haste display

The player frame's "Effective Haste" mode was hardcoded talent-position
scrapes: GetTalentInfo(1, 16) for the Mage "Accelerated Arcana"
(flat 5%) and GetTalentInfo(1, 14) for the Warlock "Rapid Deterioration"
(3% per rank), folded into the displayed haste % via
`(1 / (modCastSpeed * modCastingTime) - 1) * 100`.

That's two problems in one:
- Hardcoded talent indices and effect percentages — brittle to any
  Turtle tree reshuffle or retune.
- Conceptually muddled: it folds gear-haste and talent-cast-reduction
  into one number that's hard to read as anything specific. The actual
  effective cast time is already shown on the cast bar via
  C_Spell.UnitCastingInfo (engine helper accounts for SpellMod op 10).

Drop modCastingTime, the LEARNED_SPELL_IN_TAB watcher frame that
maintained it, the per-class talent scrape, and the hasteMode == "2"
display branch. Collapse the now-binary "display_haste" config from a
3-option dropdown to a checkbox. Users on legacy "2" will see the
checkbox unchecked once and can re-enable with a single click.

modules/gui.lua

@@ -2380,11 +2380,7 @@ pfUI:RegisterModule("gui", function ()
 
         if c == "player" then
           CreateConfig(nil, T["Player SP/Haste Display"], nil, nil, "header")
-          CreateConfig(nil, T["Haste Display"], C.unitframes[c], "display_haste", "dropdown", {
-            "0:"..T["None"],
-            "1:"..T["Haste (cast speed increase)"],
-            "2:"..T["Effective Haste (Haste * cast time reduction)"], -- Only affects mages/warlocks I believe
-          })
+          CreateConfig(nil, T["Haste Display"], C.unitframes[c], "display_haste", "checkbox")
           CreateConfig(nil, T["Haste Display Color"], C.unitframes[c], "display_haste_color", "color")
           CreateConfig(nil, T["Display Spell Power"], C.unitframes[c], "display_spellpower", "checkbox")
           CreateConfig(nil, T["Use Custom Spell Power Color (unchecked = biggest school color)"], C.unitframes[c], "display_sp_color_override", "checkbox")

modules/player.lua

@@ -38,38 +38,6 @@ pfUI:RegisterModule("player", function ()
   playerFrame.myclass = myclass
   playerFrame.isSpellCaster = myclass ~= "WARRIOR" and myclass ~= "ROGUE" and myclass ~= "HUNTER"
 
-  -- Compute class-based casting speed modifier and cache on the frame.
-  -- This is re-evaluated on LEARNED_SPELL_IN_TAB (with 1s delay) so talent changes are handled.
-  -- Not sure if there are any other effects that give % cast reduction time
-  local function UpdatePlayerModCastingTime()
-    playerFrame.modCastingTime = 1
-    if myclass == "MAGE" then
-      local _, _, _, _, acceleratedArcana = GetTalentInfo(1, 16)
-      if acceleratedArcana and acceleratedArcana > 0 then
-        playerFrame.modCastingTime = 0.95
-      end
-    elseif myclass == "WARLOCK" then
-      local _, _, _, _, rapidDeter = GetTalentInfo(1, 14)
-      if rapidDeter and rapidDeter > 0 then
-        playerFrame.modCastingTime = 1 - (rapidDeter * 0.03)
-      end
-    end
-  end
-
-  local talentFrame = CreateFrame("Frame")
-  talentFrame:RegisterEvent("PLAYER_ENTERING_WORLD")
-  talentFrame:RegisterEvent("LEARNED_SPELL_IN_TAB")
-  talentFrame:SetScript("OnEvent", function()
-    -- Delay 1s for both PLAYER_ENTERING_WORLD and LEARNED_SPELL_IN_TAB
-    local checkAt = GetTime() + 1
-    talentFrame:SetScript("OnUpdate", function()
-      if GetTime() >= checkAt then
-        talentFrame:SetScript("OnUpdate", nil)
-        UpdatePlayerModCastingTime()
-      end
-    end)
-  end)
-
   -- Convert "r,g,b,a" config color string to a 6-char hex string, or nil if unset
   local function cfgColorToHex(colorStr)
     if not colorStr or colorStr == "" then return nil end
@@ -98,26 +66,25 @@ pfUI:RegisterModule("player", function ()
     if not cfg then
       return
     end
-    local hasteMode = cfg.display_haste  -- "0"=none, "1"=modCastSpeed, "2"=modCastSpeed*modCastingTime
+    -- display_haste: "0"=hidden, "1"=show modCastSpeed (gear haste). Talent-
+    -- side cast-time reductions show up in the actual cast bar via
+    -- C_Spell.UnitCastingInfo; double-folding them into this overlay was
+    -- mixing two different concepts into one number.
+    local showHaste = cfg.display_haste == "1"
     local showSP = cfg.display_spellpower == "1"
 
     local isSpellCaster = playerFrame.isSpellCaster
-    if (hasteMode == "0" or not isSpellCaster) and not showSP then
+    if (not showHaste or not isSpellCaster) and not showSP then
       playerFrame.infoTopCenterText:SetText("")
       return
     end
 
     local haste = GetUnitField("player", "modCastSpeed")
-    local modCastingTime = playerFrame.modCastingTime or 1
     local text = ""
 
-    if isSpellCaster and haste then
+    if showHaste and isSpellCaster and haste then
       local hasteHex = cfgColorToHex(cfg.display_haste_color) or "FFFFFF"
-      if hasteMode == "1" then
-        text = string.format("|cff%s%.1f%%|r", hasteHex, (1 / haste - 1) * 100)
-      elseif hasteMode == "2" then
-        text = string.format("|cff%s%.1f%%|r", hasteHex, (1 / (haste * modCastingTime) - 1) * 100)
-      end
+      text = string.format("|cff%s%.1f%%|r", hasteHex, (1 / haste - 1) * 100)
     end
 
     if showSP and isSpellCaster then