feat: support Java prompt_context passthrough (Plan A)

- content_generate_v2: use Java prompt_context if provided, fallback to local
- topic_generate_v2: same passthrough support
- Maintains backward compatibility with direct Python calls

domain/aigc/engines/content_generate_v2.py

@@ -121,6 +121,9 @@ class ContentGenerateEngineV2(BaseAIGCEngine):
             self.log("开始生成内容 (V2)")
             self.set_progress(task_id, 10)
             
+            # 🎯 方案A: 检查是否有 Java 透传的 prompt_context
+            prompt_context = params.get('prompt_context')
+            
             # 提取参数
             topic = params.get('topic', {})
             
@@ -149,6 +152,17 @@ class ContentGenerateEngineV2(BaseAIGCEngine):
             # 获取 PromptRegistry
             prompt_registry = self._get_prompt_registry()
             
+            # 🎯 方案A: 如果有 Java 透传的 context，直接使用；否则本地构建
+            if prompt_context:
+                self.log("使用 Java 透传的 prompt_context")
+                context = prompt_context
+                # 补充可能缺少的字段
+                if 'hot_topics' not in context and hot_topics:
+                    context['hot_topics'] = hot_topics
+                if 'reference' not in context and reference:
+                    context['reference'] = reference
+            else:
+                self.log("使用本地构建的 context (兼容模式)")
                 # 从 subject 提取产品信息
                 current_product = None
                 if subject and subject.get('products'):

domain/aigc/engines/topic_generate_v2.py

@@ -158,6 +158,21 @@ class TopicGenerateEngineV2(BaseAIGCEngine):
             # 获取 PromptRegistry
             prompt_registry = self._get_prompt_registry()
             
+            # 🎯 方案A: 检查是否有 Java 透传的 prompt_context
+            prompt_context = params.get('prompt_context')
+            
+            if prompt_context:
+                self.log("使用 Java 透传的 prompt_context")
+                context = prompt_context
+                # 补充必要字段
+                if 'num_topics' not in context:
+                    context['num_topics'] = num_topics
+                if 'month' not in context:
+                    context['month'] = month
+                if 'hot_topics' not in context and hot_topics:
+                    context['hot_topics'] = hot_topics
+            else:
+                self.log("使用本地构建的 context (兼容模式)")
                 # 构建 prompt 上下文
                 context = {
                     'num_topics': num_topics,