fix: prevent detail prompt pack guard self-trigger

app/(chat)/api/chat/_lib/detail-replacement.ts

@@ -639,7 +639,6 @@ function inferPeoplePolicy(params: {
 
 function planTextForPolicyGuards(scenePlan: ReplacementScenePlan) {
   return [
-    scenePlan.routeReason,
     scenePlan.sceneSummary,
     scenePlan.cameraSummary,
     scenePlan.placementSummary,
@@ -683,6 +682,9 @@ function applyDetailReplacementScenePlanGuards(
 
   const isProductOnly = params.replacementStrategy === "product_only";
   const planText = planTextForPolicyGuards(scenePlan);
+  const alreadyAllowsPromptPack =
+    scenePlan.generationRoute === "prompt_pack_scene" &&
+    scenePlan.promptPackPolicy !== "forbid";
   const hasWhiteLayoutHint = DETAIL_WHITE_LAYOUT_HINT_PATTERN.test(planText);
   const hasPeopleActionHint = DETAIL_PEOPLE_ACTION_HINT_PATTERN.test(planText);
   const shouldProtectWhiteLayout =
@@ -692,9 +694,9 @@ function applyDetailReplacementScenePlanGuards(
       hasWhiteLayoutHint);
   const shouldProtectPeople =
     !isProductOnly &&
-    (scenePlan.peoplePolicy !== "none" ||
-      params.containsPeople ||
+    (params.containsPeople ||
       params.containsMultiplePeople ||
+      (!alreadyAllowsPromptPack && scenePlan.peoplePolicy !== "none") ||
       hasPeopleActionHint);
   const shouldLockCopy =
     !isProductOnly &&
@@ -1003,7 +1005,7 @@ export function buildHeuristicReplacementScenePlan(params: {
         : isDetailReplacement
           ? shouldProtectFallbackLayout
             ? "兜底命中白底/说明/强文案特征，按详情版式保护执行，不使用词包。"
-            : "兜底未命中白底、强文案或明确人物关系，按通用场景图执行词包场景替换。"
+            : "兜底未命中白底、强文案或真人互动硬约束，按通用场景图执行词包场景替换。"
           : "兜底未检测到强约束，允许使用词包生成场景。"
       : params.reason,
     selectedProductImageIndexes: productImageSelection.selectedProductImageIndexes,