feat: 新增风险图谱算法与系统仪表盘及操作反馈体系

后端新增风险图谱算法模块、风险观察与反馈服务、规则 DSL
校验器和可解释性引擎，完善系统仪表盘和财务仪表盘统计，
优化 agent 运行和编排执行链路，清理旧开发文档，前端新增
系统趋势、负载热力图等多种仪表盘图表组件，完善操作反馈
对话框和工作台日期选择器，优化报销创建和审批详情交互，
补充单元测试覆盖。

server/src/app/api/v1/endpoints/risk_observations.py

@@ -0,0 +1,146 @@
+from __future__ import annotations
+
+from typing import Annotated
+
+from fastapi import APIRouter, Depends, HTTPException, Query, status
+from sqlalchemy.orm import Session
+
+from app.api.deps import get_db
+from app.schemas.common import ErrorResponse
+from app.schemas.risk_observation import (
+    RiskObservationDashboardRead,
+    RiskObservationFeedbackCreate,
+    RiskObservationFeedbackRead,
+    RiskObservationListRead,
+    RiskObservationRead,
+)
+from app.services.risk_observations import RiskObservationService
+
+router = APIRouter(prefix="/risk-observations")
+DbSession = Annotated[Session, Depends(get_db)]
+
+
+@router.get(
+    "",
+    response_model=RiskObservationListRead,
+    summary="查询风险观察列表",
+    description="按单据、风险等级、风险信号、状态和来源筛选统一风险观察池。",
+)
+def list_risk_observations(
+    db: DbSession,
+    claim_id: Annotated[str | None, Query(max_length=80)] = None,
+    run_id: Annotated[str | None, Query(max_length=80)] = None,
+    execution_log_id: Annotated[str | None, Query(max_length=80)] = None,
+    risk_level: Annotated[str | None, Query(max_length=20)] = None,
+    risk_signal: Annotated[str | None, Query(max_length=100)] = None,
+    status_value: Annotated[
+        str | None,
+        Query(alias="status", max_length=30),
+    ] = None,
+    source: Annotated[str | None, Query(max_length=60)] = None,
+    limit: Annotated[int, Query(ge=1, le=200)] = 50,
+    offset: Annotated[int, Query(ge=0)] = 0,
+) -> RiskObservationListRead:
+    items, total = RiskObservationService(db).list_observations(
+        claim_id=claim_id,
+        run_id=run_id,
+        execution_log_id=execution_log_id,
+        risk_level=risk_level,
+        risk_signal=risk_signal,
+        status=status_value,
+        source=source,
+        limit=limit,
+        offset=offset,
+    )
+    return RiskObservationListRead(items=items, total=total, limit=limit, offset=offset)
+
+
+@router.get(
+    "/dashboard",
+    response_model=RiskObservationDashboardRead,
+    summary="查询风险看板聚合",
+    description="返回风险观察池的总量、分布、算法效果和近期高风险记录。",
+)
+def summarize_risk_observations(
+    db: DbSession,
+    window_days: Annotated[int, Query(ge=1, le=365)] = 30,
+    limit: Annotated[int, Query(ge=1, le=2000)] = 500,
+) -> RiskObservationDashboardRead:
+    return RiskObservationService(db).summarize_dashboard(
+        window_days=window_days,
+        limit=limit,
+    )
+
+
+@router.get(
+    "/claim/{claim_id}",
+    response_model=list[RiskObservationRead],
+    summary="查询单据风险观察",
+    description="按报销单 ID 返回该单据关联的风险观察，供单据详情证据链使用。",
+)
+def list_claim_risk_observations(claim_id: str, db: DbSession) -> list[RiskObservationRead]:
+    return RiskObservationService(db).list_claim_observations(claim_id)
+
+
+@router.get(
+    "/execution-log/{execution_log_id}",
+    response_model=list[RiskObservationRead],
+    summary="查询数字员工工作记录风险观察",
+    description="按数字员工执行日志 ID 返回本次任务生成的风险观察。",
+)
+def list_execution_log_risk_observations(
+    execution_log_id: str,
+    db: DbSession,
+) -> list[RiskObservationRead]:
+    return RiskObservationService(db).list_execution_log_observations(execution_log_id)
+
+
+@router.get(
+    "/{observation_key_or_id}",
+    response_model=RiskObservationRead,
+    summary="读取风险观察详情",
+    description="按观察 key 或 ID 返回风险评分、证据链、图谱节点、制度引用和决策追踪。",
+    responses={
+        status.HTTP_404_NOT_FOUND: {
+            "model": ErrorResponse,
+            "description": "风险观察不存在。",
+        }
+    },
+)
+def get_risk_observation(
+    observation_key_or_id: str,
+    db: DbSession,
+) -> RiskObservationRead:
+    observation = RiskObservationService(db).get_observation(observation_key_or_id)
+    if observation is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Risk observation not found",
+        )
+    return observation
+
+
+@router.post(
+    "/{observation_key_or_id}/feedback",
+    response_model=RiskObservationFeedbackRead,
+    summary="写入风险观察反馈",
+    description="记录人工确认、误报、忽略、已处理或备注反馈，并同步更新观察状态。",
+    responses={
+        status.HTTP_404_NOT_FOUND: {
+            "model": ErrorResponse,
+            "description": "风险观察不存在。",
+        }
+    },
+)
+def create_risk_observation_feedback(
+    observation_key_or_id: str,
+    payload: RiskObservationFeedbackCreate,
+    db: DbSession,
+) -> RiskObservationFeedbackRead:
+    try:
+        return RiskObservationService(db).create_feedback(observation_key_or_id, payload)
+    except LookupError:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Risk observation not found",
+        ) from None