new_editor: unify shared UI text measurement semantics

new_editor/include/XCEditor/Viewport/UIEditorViewportShell.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <XCEditor/Foundation/UIEditorTextMeasurement.h>
 #include <XCEditor/Viewport/UIEditorViewportInputBridge.h>
 #include <XCEditor/Viewport/UIEditorViewportSlot.h>
 
@@ -42,6 +43,11 @@ struct UIEditorViewportShellFrame {
     ::XCEngine::UI::UISize requestedViewportSize = {};
 };
 
+UIEditorViewportShellModel ResolveUIEditorViewportShellMeasuredModel(
+    const UIEditorViewportShellModel& model,
+    const Widgets::UIEditorViewportSlotMetrics& metrics = {},
+    const UIEditorTextMeasurer* textMeasurer = nullptr);
+
 UIEditorViewportShellRequest ResolveUIEditorViewportShellRequest(
     const ::XCEngine::UI::UIRect& bounds,
     const UIEditorViewportShellSpec& spec,

new_editor/include/XCEditor/Viewport/UIEditorViewportSlot.h

@@ -53,7 +53,8 @@ struct UIEditorViewportSlotToolItem {
     UIEditorViewportSlotToolSlot slot = UIEditorViewportSlotToolSlot::Trailing;
     bool enabled = true;
     bool selected = false;
-    float desiredWidth = 0.0f;
+    // Pure measured tool-label width. Tool button padding is applied only in layout.
+    float measuredLabelWidth = 0.0f;
 };
 
 struct UIEditorViewportSlotState {
@@ -75,13 +76,18 @@ struct UIEditorViewportSlotMetrics {
     float toolPaddingX = 8.0f;
     float toolGap = 4.0f;
     float toolCornerRounding = 2.0f;
+    float toolLabelFontSize = 11.0f;
+    float toolLabelInsetY = 3.0f;
     float titleGap = 6.0f;
+    float titleFontSize = 13.0f;
     float titleInsetY = 5.0f;
+    float subtitleFontSize = 10.0f;
     float subtitleInsetY = 14.0f;
     float estimatedGlyphWidth = 6.5f;
     float surfaceInset = 0.0f;
     float surfaceBorderThickness = 1.0f;
     float focusedSurfaceBorderThickness = 1.0f;
+    UIEditorStatusBarMetrics statusBarMetrics = {};
 };
 
 struct UIEditorViewportSlotPalette {
@@ -157,6 +163,11 @@ struct UIEditorViewportSlotForegroundAppendOptions {
     bool includeSurfaceTexture = true;
 };
 
+float ResolveUIEditorViewportSlotMeasuredToolLabelWidth(
+    const UIEditorViewportSlotToolItem& item,
+    const UIEditorViewportSlotMetrics& metrics = {},
+    const UIEditorTextMeasurer* textMeasurer = nullptr);
+
 float ResolveUIEditorViewportSlotDesiredToolWidth(
     const UIEditorViewportSlotToolItem& item,
     const UIEditorViewportSlotMetrics& metrics = {});