fix(settings): let the preview show what the log shows

The preview was four flat lines of text on a plain field. After this cycle the
real log has a channel header above it, a fixed timestamp column, and system
messages in italics -- so the preview had quietly become a picture of a window
that no longer exists. That is the same defect as a widget with no call site,
just pointing the other way: something on screen that stopped tracking what it
describes.

The reserved band grew with it. It is a fixed height that the sidebar mock also
divides by, so adding a row inside without raising it would have pushed the last
message out of the space -- the recurring drawing-into-unreserved-space mistake
this project keeps stepping on.

Preview stamps are fixed rather than live. A clock ticking inside a settings
panel pulls the eye away from the setting being changed.

HellionChat/Ui/Components/Settings/LivePreviewPanel.cs

@@ -26,15 +26,25 @@ internal sealed class LivePreviewPanel : IDisposable
     internal static int InstanceCount;
 
     // Plan-mandated mock strings — international tester-ready, do not localise.
-    private const string MockSystem = "System: Connection established";
+    private const string MockSystem = "Connection established";
     private const string MockSay = "Say: Hello, world!";
     private const string MockTell = "Tell → Player: Hey, want to party?";
     private const string MockFc = "FC: Welcome aboard.";
 
+    // The stamps the preview shows against its own rows. Fixed rather than live:
+    // a clock ticking inside a settings preview draws the eye away from the
+    // setting being changed.
+    private static readonly string[] MockStamps = ["22:10", "22:14", "22:15", "22:17"];
+
+    private const string MockChannel = "GENERAL";
+
     // Crown/cog render via the FontAwesome font (FontManager) so the preview
     // matches the real header glyphs; the bundled text font has no crown glyph.
 
-    private const float MiddleBandHeight = 220f;
+    // Grew with the channel header: the band is reserved as a fixed height and
+    // the sidebar mock divides by it, so a row added inside without raising this
+    // would have pushed the last message out of the reserved space.
+    private const float MiddleBandHeight = 248f;
     private const float SidebarWidth = 70f;
 
     private readonly ThemeRegistry _themes;
@@ -259,6 +269,29 @@ internal sealed class LivePreviewPanel : IDisposable
 
         draw.AddRectFilled(listOrigin, max, ColourUtil.RgbaToAbgr(theme.Colors.WindowBg));
 
+        // The channel header the real window now carries above its log. Tracked
+        // caps, same as the widget draws them.
+        var headerHeight = ImGui.GetTextLineHeight() + 8f;
+        draw.AddRectFilled(
+            listOrigin,
+            new Vector2(max.X, listOrigin.Y + headerHeight),
+            ColourUtil.RgbaToAbgr(theme.Colors.Surface)
+        );
+        draw.AddLine(
+            new Vector2(listOrigin.X, listOrigin.Y + headerHeight),
+            new Vector2(max.X, listOrigin.Y + headerHeight),
+            ColourUtil.RgbaToAbgr(theme.Colors.Border),
+            1f
+        );
+        draw.DrawTrackedText(
+            new Vector2(listOrigin.X + 6f, listOrigin.Y + 4f),
+            MockChannel,
+            ColourUtil.RgbaToAbgr(
+                ColourUtil.EnsureContrast(theme.Colors.Accent, theme.Colors.Surface, 4.5f)
+            ),
+            1.8f
+        );
+
         var padMin = new Vector2(listOrigin.X + 2f, max.Y - 6f);
         draw.AddRectFilled(
             padMin,
@@ -274,11 +307,40 @@ internal sealed class LivePreviewPanel : IDisposable
             (MockFc, theme.Colors.StatusSuccess),
         ];
 
+        // A fixed stamp column, like the log has, so the senders line up in the
+        // preview the same way they line up for real.
+        var stampWidth = ImGui.CalcTextSize(TimestampColumn.SampleFor(true)).X + 8f;
         var lineHeight = ImGui.GetTextLineHeightWithSpacing();
+        var textTop = listOrigin.Y + headerHeight + 4f;
+
+        var fonts = Plugin.Instance.FontManager;
+        var italic =
+            Plugin.Config.FontsEnabled && fonts.ItalicFont is not null
+                ? fonts.ItalicFont
+                : fonts.AxisItalic;
+
         for (var i = 0; i < rows.Length; i++)
         {
-            var pos = new Vector2(listOrigin.X + 6f, listOrigin.Y + 6f + i * lineHeight);
-            draw.AddText(pos, ColourUtil.RgbaToAbgr(rows[i].Rgba), rows[i].Text);
+            var y = textTop + i * lineHeight;
+            draw.AddText(
+                new Vector2(listOrigin.X + 6f, y),
+                ColourUtil.RgbaToAbgr(theme.Colors.TextDim),
+                MockStamps[i]
+            );
+
+            var textPos = new Vector2(listOrigin.X + 6f + stampWidth, y);
+            var colour = ColourUtil.RgbaToAbgr(rows[i].Rgba);
+
+            // Row zero is the system line, and the log draws those in italics.
+            if (i == 0)
+            {
+                using (italic.Push())
+                    draw.AddText(textPos, colour, rows[i].Text);
+            }
+            else
+            {
+                draw.AddText(textPos, colour, rows[i].Text);
+            }
         }
 
         draw.AddLine(