feat: variables 2.0 state + L0 summary integration

modules/variables/state2/semantic.js

@@ -0,0 +1,42 @@
+export function generateSemantic(path, op, oldValue, newValue, delta, operandValue) {
+    const p = String(path ?? '').replace(/\./g, ' > ');
+
+    const fmt = (v) => {
+        if (v === undefined) return '空';
+        if (v === null) return 'null';
+        try {
+            if (typeof v === 'string') return JSON.stringify(v);
+            return JSON.stringify(v);
+        } catch {
+            return String(v);
+        }
+    };
+
+    switch (op) {
+        case 'set':
+            return oldValue === undefined
+                ? `${p} 设为 ${fmt(newValue)}`
+                : `${p} 从 ${fmt(oldValue)} 变为 ${fmt(newValue)}`;
+
+        case 'inc': {
+            const sign = (delta ?? 0) >= 0 ? '+' : '';
+            return `${p} ${sign}${delta}（${fmt(oldValue)} → ${fmt(newValue)}）`;
+        }
+
+        case 'push': {
+            const items = Array.isArray(operandValue) ? operandValue : [operandValue];
+            return `${p} 加入 ${items.map(fmt).join('、')}`;
+        }
+
+        case 'pop': {
+            const items = Array.isArray(operandValue) ? operandValue : [operandValue];
+            return `${p} 移除 ${items.map(fmt).join('、')}`;
+        }
+
+        case 'del':
+            return `${p} 被删除（原值 ${fmt(oldValue)}）`;
+
+        default:
+            return `${p} 操作 ${op}`;
+    }
+}