接入 OTel 链路追踪 + 镜像默认启用

抓取-解析链路原本只有日志，出现"抓回内容但解析不出预期字段"时定位慢。
接入 OpenTelemetry traces（FastAPI/httpx 自动 + 手写 fetch/parse span），
解析失败时把页面 HTML 作为 span event 上报，便于事后复现。
Dockerfile 默认开启，镜像一启动即导出到自建 OTLP endpoint。

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/trading/main.py

@@ -22,6 +22,7 @@ from fastapi import FastAPI
 from app.shared.api import register_exception_handlers
 from app.shared.config import get_settings
 from app.shared.logging_setup import configure_logging
+from app.shared.telemetry import instrument_app, setup_telemetry, shutdown_telemetry
 from app.trading.api.routes.auth import router as auth_router
 from app.trading.api.routes.health import router as health_router
 from app.trading.container import TradingContainer
@@ -43,6 +44,8 @@ async def lifespan(app: FastAPI):
     app.state.container = container
 
     configure_logging(container.settings)
+    # 与抓取侧同样：必须在创建 httpx 客户端之前 setup。
+    setup_telemetry(container.settings, service_name="rakuten-trading")
     logger.info(
         "交易服务启动：%s:%s",
         container.settings.trading_host,
@@ -54,6 +57,7 @@ async def lifespan(app: FastAPI):
         yield
     finally:
         await container.auth_session.close()
+        shutdown_telemetry()
 
 
 def create_app() -> FastAPI:
@@ -62,6 +66,7 @@ def create_app() -> FastAPI:
     app.include_router(health_router)
     app.include_router(auth_router)
     register_exception_handlers(app)
+    instrument_app(app)
     return app