fix(input-preview): wire Inside-mode + Tooltip-mode render paths

InputPreview was only rendered for PreviewPosition.Top/Bottom (the
DrawConditions IsWindowMode gate). Inside-mode (the default) and
Tooltip-mode had no caller at all because v1.5.6's inline-render path
lived on the deleted ChatLogWindow and was not migrated to the v1.7.0
Components-Layer.

Wire Inside-mode by calling CalculatePreviewHeight + DrawPreview
inline from MainWindow.DrawMainArea between the message-list child
and the input bar, with the message-list height reserved for the
preview block. Wire Tooltip-mode by sampling IsItemHovered() on the
input text widget inside InputBar.DrawInputField (analog to the
existing _isFocused = ImGui.IsItemFocused() idiom on the same line)
and exposing it as WasInputTextHovered; MainWindow opens the tooltip
after _input.Draw when both the hover-flag and PreviewPosition.Tooltip
are active.

Plan-drift acknowledged: the plan stated Plugin.InputPreview is
statically reachable, but the property was declared as an instance
member on Plugin.cs:101. Hoisted to internal static to match the
plan's intention (analog to Plugin.Config); updated the single
external instance-access site in PluginLifecycle.RegisterWindows
to the type-qualified form.

Verified in-game: Inside-mode preview block appears between message
list and input bar on first keystroke; tooltip-mode shows preview on
text-field hover only; Top/Bottom-mode unchanged; empty buffer hides
the preview in all modes. dotnet build clean, dotnet csharpier check
clean.

HellionChat/Ui/Components/InputBar.cs

@@ -37,6 +37,7 @@ internal sealed class InputBar
 
     private string _pendingMessage = string.Empty;
     private bool _isFocused;
+    private bool _wasInputTextHovered;
     private bool? _isFocusedOverride; // Test-only; null = honour per-frame Draw() value.
 
     public bool Activate;
@@ -74,6 +75,10 @@ internal sealed class InputBar
     // rest of the component doesn't need.
     public bool IsFocused => _isFocusedOverride ?? _isFocused;
 
+    // Sampled in DrawInputField() right after ImGui.InputText so the value
+    // reflects the text widget, not a later QuickButton item.
+    public bool WasInputTextHovered => _wasInputTextHovered;
+
     public void ClearBuffer() => _pendingMessage = string.Empty;
 
     // BufferCapacity is an ImGui UX limit, not a protocol constraint. We
@@ -235,6 +240,7 @@ internal sealed class InputBar
             TrySend(activeTab);
         }
         _isFocused = ImGui.IsItemFocused();
+        _wasInputTextHovered = ImGui.IsItemHovered();
     }
 
     // v1.5.6 character-level slash-detect: fires on every edit so CommandHelpWindow