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/services/employee_behavior_profile_helpers.py

@@ -9,6 +9,7 @@ from app.algorithem.employee_behavior_profile import ALGORITHM_VERSION
 from app.models.agent_run import AgentRun
 from app.models.employee import Employee
 from app.models.financial_record import ExpenseClaim
+from app.services.user_session_metrics import UserSessionMetricService
 
 TRAVEL_EXPENSE_TYPES = {
     "travel",
@@ -174,6 +175,50 @@ class EmployeeBehaviorProfileMetricHelpers:
     def _sum_agent_run_duration_ms(self, runs: list[AgentRun]) -> int:
         return sum(self._agent_run_duration_ms(run) for run in runs)
 
+    def _resolve_usage_duration_metrics(
+        self,
+        identifiers: set[str],
+        cutoff: Any,
+        runs: list[AgentRun],
+    ) -> dict[str, Any]:
+        ai_duration_ms = self._sum_agent_run_duration_ms(runs)
+        online_duration_ms = UserSessionMetricService(self.db).sum_duration_ms(identifiers, cutoff)
+        if online_duration_ms > 0:
+            usage_duration_ms = online_duration_ms
+            usage_duration_mode = "online_session"
+        else:
+            usage_duration_ms = ai_duration_ms
+            usage_duration_mode = "agent_run_fallback"
+        return {
+            "online_duration_ms": online_duration_ms,
+            "usage_duration_ms": usage_duration_ms,
+            "usage_duration_mode": usage_duration_mode,
+            "ai_run_duration_ms": ai_duration_ms,
+            "ai_run_duration_mode": "elapsed_or_tool_call_fallback",
+        }
+
+    def _merge_live_usage_duration_metrics(
+        self,
+        payloads: list[dict[str, Any]],
+        identifiers: set[str],
+        cutoff: Any,
+    ) -> list[dict[str, Any]]:
+        online_duration_ms = UserSessionMetricService(self.db).sum_duration_ms(identifiers, cutoff)
+        if online_duration_ms <= 0:
+            return payloads
+
+        next_payloads: list[dict[str, Any]] = []
+        for payload in payloads:
+            if payload.get("profile_type") != "ai_usage":
+                next_payloads.append(payload)
+                continue
+            metrics = dict(payload.get("metrics") or {})
+            metrics["online_duration_ms"] = online_duration_ms
+            metrics["usage_duration_ms"] = online_duration_ms
+            metrics["usage_duration_mode"] = "online_session"
+            next_payloads.append({**payload, "metrics": metrics})
+        return next_payloads
+
     def _agent_run_duration_ms(self, run: AgentRun) -> int:
         if run.started_at is not None and run.finished_at is not None:
             try: