Fix flat raid frames using party settings instead of raid settings

CreateFrames() and RefreshLayout() were missing the isRaidFrame flag
on child frames, causing GetFrameDB() to fall through to party settings.

Author: DanderBot

Changelog.lua

@@ -1,5 +1,5 @@
 local addonName, DF = ...
-DF.BUILD_DATE = "2026-03-20T12:50:51Z"
+DF.BUILD_DATE = "2026-03-20T13:42:15Z"
 DF.RELEASE_CHANNEL = "alpha"
 DF.CHANGELOG_TEXT = [===[
 # DandersFrames Changelog

Features/FlatRaidFrames.lua

@@ -483,6 +483,7 @@ function FlatRaidFrames:CreateFrames()
         if child then
             childCount = childCount + 1
             child:SetSize(frameWidth, frameHeight)
+            child.isRaidFrame = true
         end
     end
     DebugPrint("Created", childCount, "child frames, sized to", frameWidth, "x", frameHeight)
@@ -733,11 +734,12 @@ function FlatRaidFrames:RefreshLayout()
 
     DebugPrint("RefreshLayout - resizing children and toggling startingIndex")
 
-    -- FIRST: Resize all child frames (needed for proper positioning)
+    -- FIRST: Resize all child frames and sync isRaidFrame flag (needed for proper positioning)
     for i = 1, 40 do
         local child = header:GetAttribute("child" .. i)
         if child then
             child:SetSize(frameWidth, frameHeight)
+            child.isRaidFrame = true
         end
     end