fix: code compliance audit and fix across all services

NestJS (6 services): implement @RequirePermission decorator with
SetMetadata+Reflector, register APP_GUARD globally, fix as assertions
to type guards, add explicit return types, fix import type for express,
fix /metrics implicit any, replace native Error with ApplicationError,
remove typeorm remnants, register LifecycleService.

teacher-bff: add logger, ApplicationError, GlobalErrorFilter, forward
real userId to downstream, log downstream failures, migrate health
controller to shared/health.

Go (2 services): interface to any, doc comments, CORS dev whitelist,
JWT secret fail-fast, push-gateway internal API auth, metrics and
readyz endpoints, remove dead code.

Python (2 services): lifespan return type, dev_mode to bool, data-ana
APIRouter, ai POST body model, ClickHouse async wrapping.

services/data-ana/src/data_ana/main.py

@@ -9,11 +9,12 @@
 
 import asyncio
 import contextlib
+from collections.abc import AsyncGenerator
 from contextlib import asynccontextmanager
 from datetime import UTC, datetime
 
 import structlog
-from fastapi import FastAPI
+from fastapi import APIRouter, FastAPI
 from opentelemetry import trace
 from opentelemetry.exporter.otlp.proto.http.trace_exporter import OTLPSpanExporter
 from opentelemetry.instrumentation.fastapi import FastAPIInstrumentor
@@ -89,7 +90,7 @@ def init_tracer() -> None:
 
 
 @asynccontextmanager
-async def lifespan(app: FastAPI):
+async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
     """应用生命周期.
 
     1. 初始化 logger（structlog）
@@ -133,6 +134,9 @@ FastAPIInstrumentor.instrument_app(app)
 # Prometheus 指标
 app.mount("/metrics", make_asgi_app())
 
+# 业务路由
+router = APIRouter()
+
 
 @app.get("/healthz")
 async def healthz() -> dict:
@@ -189,7 +193,7 @@ async def readyz() -> dict:
     }
 
 
-@app.get("/analytics/class/{class_id}/performance")
+@router.get("/analytics/class/{class_id}/performance")
 async def class_performance(class_id: str) -> dict:
     """班级成绩分析.
 
@@ -215,7 +219,7 @@ async def class_performance(class_id: str) -> dict:
         return {"success": True, "data": {**result, "degraded": False}}
 
 
-@app.get("/analytics/student/{student_id}/weakness")
+@router.get("/analytics/student/{student_id}/weakness")
 async def student_weakness(student_id: str) -> dict:
     """学生薄弱知识点分析.
 
@@ -259,7 +263,7 @@ async def student_weakness(student_id: str) -> dict:
         }
 
 
-@app.get("/analytics/student/{student_id}/errorbook")
+@router.get("/analytics/student/{student_id}/errorbook")
 async def student_errorbook(student_id: str) -> dict:
     """学生错题本.
 
@@ -290,3 +294,6 @@ async def student_errorbook(student_id: str) -> dict:
                 "degraded": False,
             },
         }
+
+
+app.include_router(router)