[阶段2] FAM-Edge 重构为整视频分析+同步接口+人物服务 - 移除切片/抽帧/队列，新增 oracle_db/person_service/qa/watch_processor/video_processor，api_gateway 提供 /api/oracle/sync 与 /api/oracle/people/correct

fam-edge/src/fam_edge/qa.py

@@ -0,0 +1,35 @@
+"""
+QA - 智能问答编排
+
+run_qa(prompt): 按 models 顺序尝试 chat()，首个成功返回 (answer, provider)。
+顺序 = vision 模型(Gemini -> NVIDIA) + text 模型(Ollama 兜底)。
+即 Gemini -> NVIDIA -> Ollama 三级降级。
+"""
+from typing import Optional, Tuple
+
+from .logger import setup_logger
+from .config_loader import load_config
+from .model_adapters.adapter_factory import build_adapters
+
+logger = setup_logger('fam-edge.qa')
+
+
+class QAOrchestrator:
+    def __init__(self):
+        self.config = load_config()
+        self.adapters = build_adapters(self.config.get('models', []))
+
+    def run_qa(self, prompt: str,
+               max_tokens: int = 1024) -> Tuple[Optional[str], Optional[str]]:
+        """依次尝试各适配器的 chat()，返回 (answer, provider)。"""
+        for adapter in self.adapters:
+            try:
+                answer = adapter.chat(prompt, max_tokens=max_tokens)
+            except Exception as e:
+                logger.warning(f"QA {adapter.provider_name} 异常: {e}")
+                continue
+            if answer:
+                logger.info(f"QA 命中 provider={adapter.provider_name}")
+                return answer, adapter.provider_name
+            logger.info(f"QA {adapter.provider_name} 无返回，降级下一模型")
+        return None, None