Step 12：后端轻量优化（API 稳定性 & 前端友好）

backend/app/api/v1/constants.py

@@ -0,0 +1,22 @@
+from fastapi import APIRouter, Depends
+
+from app.constants import ae, finance, imp, issue, subject, task
+from app.core.deps import get_current_user
+
+router = APIRouter(tags=["FAQ"], dependencies=[Depends(get_current_user)])
+
+
+@router.get(
+    "/",
+    summary="获取前端常量字典",
+    description="返回各模块状态/类型常量，便于前端一次性加载。",
+)
+async def get_constants():
+    return {
+        "task": {"status": task.TASK_STATUS, "priority": task.TASK_PRIORITY},
+        "subject": {"status": subject.SUBJECT_STATUS, "visit_status": subject.VISIT_STATUS},
+        "ae": {"seriousness": ae.AE_SERIOUSNESS, "severity": ae.AE_SEVERITY, "status": ae.AE_STATUS},
+        "issue": {"category": issue.ISSUE_CATEGORY, "level": issue.ISSUE_LEVEL, "status": issue.ISSUE_STATUS},
+        "finance": {"status": finance.FINANCE_STATUS, "category": finance.FINANCE_CATEGORY},
+        "imp": {"tx_types": imp.IMP_TX_TYPES, "batch_status": imp.IMP_BATCH_STATUS},
+    }