feat: modernize pricing UI - add index.ui with card navigation

- Create index.ui with standardized card layout (#1E293B, 12px radius)
- Simplify menu.ui to point to index.ui entry point
- Add page header with Title2 + description text
- Use consistent SVG icon style (36px, 1.5 stroke width)

wwwroot/index.ui

@@ -0,0 +1,98 @@
+{
+    "widgettype": "VBox",
+    "options": {
+        "width": "100%",
+        "height": "100%",
+        "padding": "0"
+    },
+    "subwidgets": [
+        {
+            "widgettype": "HBox",
+            "options": {
+                "width": "100%",
+                "alignItems": "center",
+                "marginBottom": "24px"
+            },
+            "subwidgets": [
+                {
+                    "widgettype": "Title2",
+                    "options": {
+                        "text": "定价管理",
+                        "color": "#F1F5F9",
+                        "fontWeight": "700"
+                    }
+                },
+                {
+                    "widgettype": "Filler"
+                },
+                {
+                    "widgettype": "Text",
+                    "options": {
+                        "text": "模型定价项目与计费规则配置",
+                        "fontSize": "14px",
+                        "color": "#64748B"
+                    }
+                }
+            ]
+        },
+        {
+            "widgettype": "VBox",
+            "options": {
+                "bgcolor": "#1E293B",
+                "padding": "24px",
+                "borderRadius": "12px",
+                "border": "1px solid #334155",
+                "cursor": "pointer"
+            },
+            "binds": [
+                {
+                    "wid": "self",
+                    "event": "click",
+                    "actiontype": "urlwidget",
+                    "target": "app.pricing_content",
+                    "options": {
+                        "url": "{{entire_url('/pricing/pricing_program')}}"
+                    },
+                    "mode": "replace"
+                }
+            ],
+            "subwidgets": [
+                {
+                    "widgettype": "Svg",
+                    "options": {
+                        "svg": "<svg width=\"36\" height=\"36\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"#F59E0B\" stroke-width=\"1.5\"><path d=\"M12 6v12m-3-2.818l.879.659c1.171.879 3.07.879 4.242 0 1.172-.879 1.172-2.303 0-3.182C13.536 12.219 12.768 12 12 12c-.725 0-1.45-.22-2.003-.659-1.106-.879-1.106-2.303 0-3.182s2.9-.879 4.006 0l.415.33M21 12a9 9 0 11-18 0 9 9 0 0118 0z\"/></svg>",
+                        "width": "36px",
+                        "height": "36px",
+                        "marginBottom": "16px"
+                    }
+                },
+                {
+                    "widgettype": "Title4",
+                    "options": {
+                        "text": "定价项目管理",
+                        "color": "#F1F5F9",
+                        "fontWeight": "600",
+                        "marginBottom": "8px"
+                    }
+                },
+                {
+                    "widgettype": "Text",
+                    "options": {
+                        "text": "管理模型定价规则、计费项目和定时任务",
+                        "fontSize": "14px",
+                        "color": "#94A3B8"
+                    }
+                }
+            ]
+        },
+        {
+            "widgettype": "VBox",
+            "id": "pricing_content",
+            "options": {
+                "width": "100%",
+                "flex": "1",
+                "marginTop": "20px"
+            }
+        }
+    ]
+}

wwwroot/menu.ui

@@ -1,16 +1,13 @@
 {
-	"widgettype": "Menu",
+    "widgettype": "Menu",
-	"options": {
+    "id": "pricing_menu",
-		"target": "PopupWindow",
+    "options": {
-		"popup_options":{
+        "items": [
-		},
+            {
-		"items":[
+                "name": "pricing",
-			{
+                "label": "定价管理",
-				"name": "pricing_program",
+                "url": "{{entire_url('/pricing/index.ui')}}"
-				"icon": "{{entire_url('/pricing/imgs/pricing_program.svg')}}",
+            }
-				"label": "定价项目管理",
+        ]
-				"url": "{{entire_url('/pricing/pricing_program')}}"
+    }
-			}
-		]
-	}
 }