feat(web): 增加参数即时估价与显式免费编辑

估价请求统一使用 350ms 防抖、AbortController 和请求序号，区分免费、计算中、价格不可用与失败状态，并展示候选冻结上限。价格未就绪时阻止生产提交。\n\n计价规则编辑器新增显式免费开关和 9 位价格步进。\n\n验证：Web 88 项测试和生产构建通过。

apps/web/src/pages/admin/PricingRuleVisualEditor.tsx

@@ -221,7 +221,17 @@ function ModeRuleEditor(props: {
           <Select size="sm" value={rule.status ?? 'active'} onChange={(event) => patch({ status: event.target.value })}>{statuses.map((item) => <option key={item} value={item}>{item}</option>)}</Select>
         </PricingFormRow>
         <PricingFormRow label={`基础单价/${unitLabel(rule.unit)}`}>
-          <Input size="sm" min="0" step="0.0001" type="number" value={rule.basePrice} onChange={(event) => patch({ basePrice: Number(event.target.value) })} />
+          <Input disabled={rule.isFree} size="sm" min="0" step="0.000000001" type="number" value={rule.basePrice} onChange={(event) => patch({ basePrice: Number(event.target.value) })} />
+        </PricingFormRow>
+        <PricingFormRow label="显式免费">
+          <label>
+            <input
+              type="checkbox"
+              checked={rule.isFree ?? false}
+              onChange={(event) => patch({ isFree: event.target.checked, basePrice: event.target.checked ? 0 : rule.basePrice })}
+            />
+            <span>允许该规则以零费用运行</span>
+          </label>
         </PricingFormRow>
         <PricingReadonlyRow label="计价单位" value={unitLabel(rule.unit)} />
         <PricingReadonlyRow label="计算方式" value={calculatorLabel(rule.calculatorType)} />
@@ -311,11 +321,32 @@ function TextRuleEditor(props: {
         <PricingFormRow label="状态">
           <Select size="sm" value={props.rule.status ?? 'active'} onChange={(event) => props.onChange({ ...props.rule, status: event.target.value })}>{statuses.map((item) => <option key={item} value={item}>{item}</option>)}</Select>
         </PricingFormRow>
+        <PricingFormRow label="显式免费">
+          <label>
+            <input
+              type="checkbox"
+              checked={props.rule.isFree ?? false}
+              onChange={(event) => {
+                const isFree = event.target.checked;
+                props.onChange({
+                  ...props.rule,
+                  isFree,
+                  basePrice: isFree ? 0 : props.rule.basePrice,
+                  formulaConfig: isFree
+                    ? { ...(props.rule.formulaConfig ?? {}), inputTokenPrice: 0, cachedInputTokenPrice: 0, outputTokenPrice: 0 }
+                    : props.rule.formulaConfig,
+                });
+              }}
+            />
+            <span>允许该规则以零费用运行</span>
+          </label>
+        </PricingFormRow>
         <PricingFormRow label="输入单价/1K tokens">
           <Input
+            disabled={props.rule.isFree}
             size="sm"
             min="0"
-            step="0.0001"
+            step="0.000000001"
             type="number"
             value={prices.inputTokenPrice}
             onChange={(event) =>
@@ -329,9 +360,10 @@ function TextRuleEditor(props: {
         </PricingFormRow>
         <PricingFormRow label="缓存输入单价/1K tokens">
           <Input
+            disabled={props.rule.isFree}
             size="sm"
             min="0"
-            step="0.0001"
+            step="0.000000001"
             type="number"
             value={prices.cachedInputTokenPrice}
             onChange={(event) =>
@@ -345,9 +377,10 @@ function TextRuleEditor(props: {
         </PricingFormRow>
         <PricingFormRow label="输出单价/1K tokens">
           <Input
+            disabled={props.rule.isFree}
             size="sm"
             min="0"
-            step="0.0001"
+            step="0.000000001"
             type="number"
             value={prices.outputTokenPrice}
             onChange={(event) =>

apps/web/src/pages/admin/PricingRulesPanel.tsx

@@ -225,6 +225,7 @@ function ruleToInput(rule: PricingRule): PricingRuleInput {
     resourceType: rule.resourceType,
     unit: rule.unit,
     basePrice: rule.basePrice,
+    isFree: rule.isFree,
     currency: rule.currency,
     baseWeight: rule.baseWeight ?? {},
     dynamicWeight: rule.dynamicWeight ?? {},
@@ -234,6 +235,8 @@ function ruleToInput(rule: PricingRule): PricingRuleInput {
     priority: rule.priority,
     status: rule.status,
     metadata: rule.metadata ?? {},
+    effectiveFrom: rule.effectiveFrom,
+    effectiveTo: rule.effectiveTo,
   };
 }