feat(server): 会话上下文保留（LLM 历史 + 确定性兜底双保险）

解决用户删除草稿后说'再提交'丢失上下文的问题： - steward.py 新增 _inject_recent_conversation_history：build_plan 前读最近 10 条对话注入 context_json - steward_intent_agent.py 的 _build_messages 把 recent_history 暴露给模型，system prompt 加确认类话术引导 - 新建 steward_context_resume.py：should_resume_recent_task 检测'再提交'类话术 + state 有可恢复 flow，attach_resumed_task 从 state 恢复 task - 两个 plan 入口（/plans 和 /plans/stream）都已接入双保险 - 后端 67 passed，端到端验证'上海出差→再提交'成功恢复 task
2026-06-25 15:08:56 +08:00
parent 2ebc2756bf
commit e9d7c56d5b
5 changed files with 440 additions and 0 deletions
--- a/server/src/app/services/steward_context_resume.py
+++ b/server/src/app/services/steward_context_resume.py
@@ -0,0 +1,170 @@
+from __future__ import annotations
+
+import re
+from typing import Any
+
+from app.schemas.steward import (
+    StewardPlanResponse,
+    StewardTask,
+    StewardThinkingEvent,
+)
+
+
+# "再提交"类确认话术：用户在删除草稿/解决冲突后，用这些话术恢复之前的申请 task
+RESUME_CONFIRMATION_KEYWORDS = (
+    "再提交",
+    "继续提交",
+    "重新提交",
+    "再申请",
+    "继续申请",
+    "重新申请",
+    "那就提交",
+    "那就申请",
+    "继续吧",
+    "再试一次",
+    "重新发起",
+    "重新创建",
+)
+
+# flow_id → task_type 映射，用于从 steward_state 恢复 task
+_FLOW_TASK_TYPE = {
+    "travel_application": "expense_application",
+    "travel_reimbursement": "reimbursement",
+}
+
+_FLOW_ASSIGNED_AGENT = {
+    "travel_application": "application_assistant",
+    "travel_reimbursement": "reimbursement_assistant",
+}
+
+
+def should_resume_recent_task(
+    message: str,
+    steward_state: dict[str, Any] | None,
+) -> str | None:
+    """检测'再提交'类话术 + steward_state 里有可恢复的 flow，返回 flow_id 或 None。
+
+    确定性兜底：不依赖 LLM，当用户用确认类话术（如"再提交"）且 state 里存在
+    一个仍有业务字段的 flow 时，直接恢复该 flow。
+    """
+    if not _matches_resume_keywords(message):
+        return None
+    if not isinstance(steward_state, dict):
+        return None
+
+    active_flow = str(steward_state.get("active_flow") or "").strip()
+    flows = steward_state.get("flows") if isinstance(steward_state.get("flows"), dict) else {}
+
+    # 优先恢复 active_flow，其次遍历所有 flow 找最近一个有字段的
+    candidate_flow_ids: list[str] = []
+    if active_flow and active_flow in flows:
+        candidate_flow_ids.append(active_flow)
+    for flow_id in flows:
+        if flow_id not in candidate_flow_ids:
+            candidate_flow_ids.append(flow_id)
+
+    for flow_id in candidate_flow_ids:
+        flow = flows.get(flow_id)
+        if isinstance(flow, dict) and _flow_has_resumable_fields(flow):
+            return str(flow_id or "").strip() or None
+    return None
+
+
+def resume_task_from_flow(
+    flow_id: str,
+    flow: dict[str, Any],
+    task_index: int = 1,
+) -> StewardTask:
+    """从 steward_state.flows[flow_id] 恢复成 StewardTask。
+
+    复用 runtime-decision 的恢复逻辑（_hydrate_runtime_state 的 field 读取），
+    但产出完整 StewardTask 而非 runtime dict。
+    """
+    task_type = _FLOW_TASK_TYPE.get(flow_id, "expense_application")
+    assigned_agent = _FLOW_ASSIGNED_AGENT.get(flow_id, "application_assistant")
+    fields = {
+        str(key or "").strip(): str(value or "").strip()
+        for key, value in (flow.get("fields") or {}).items()
+        if str(key or "").strip() and str(value or "").strip()
+    }
+    missing_fields = [
+        str(item or "").strip()
+        for item in (flow.get("missing_fields") or [])
+        if str(item or "").strip()
+    ]
+    task_prefix = "app" if task_type == "expense_application" else "reim"
+    return StewardTask(
+        task_id=f"task_resume_{task_prefix}_{task_index:03d}",
+        task_type=task_type,
+        assigned_agent=assigned_agent,
+        title="恢复上次未完成的申请" if task_type == "expense_application" else "恢复上次未完成的报销",
+        summary="根据之前的对话上下文恢复该任务。",
+        status="needs_confirmation" if missing_fields else "ready_to_delegate",
+        confidence=0.85,
+        requested_action="submit",
+        ontology_fields=fields,
+        missing_fields=missing_fields,
+        confirmation_required=True,
+    )
+
+
+def attach_resumed_task(
+    plan: StewardPlanResponse,
+    steward_state: dict[str, Any] | None,
+    flow_id: str,
+) -> StewardPlanResponse:
+    """把恢复的 task 挂回 plan，并补充一条 thinking_event 说明上下文已恢复。"""
+    if not isinstance(steward_state, dict):
+        return plan
+    flows = steward_state.get("flows") if isinstance(steward_state.get("flows"), dict) else {}
+    flow = flows.get(flow_id) if isinstance(flows, dict) else None
+    if not isinstance(flow, dict):
+        return plan
+
+    resumed_task = resume_task_from_flow(flow_id, flow, task_index=len(plan.tasks) + 1)
+    tasks = list(plan.tasks) + [resumed_task]
+
+    thinking_events = list(plan.thinking_events)
+    field_summary = "、".join(
+        f"{key}:{value}" for key, value in resumed_task.ontology_fields.items() if value
+    )
+    thinking_events.append(
+        StewardThinkingEvent(
+            event_id="context_resume_recovered",
+            stage="llm_function_call",
+            title="已恢复上次未完成的申请",
+            content=(
+                f"识别到您要继续之前的{('出差申请' if resumed_task.task_type == 'expense_application' else '费用报销')}，"
+                f"已从会话上下文恢复该任务"
+                + (f"（{field_summary}）。" if field_summary else "。")
+            ),
+            status="completed",
+        )
+    )
+
+    return plan.model_copy(
+        update={
+            "tasks": tasks,
+            "thinking_events": thinking_events,
+            "planning_source": "context_resume",
+            "next_action": "confirm_task" if resumed_task.missing_fields else "delegate_task",
+        }
+    )
+
+
+def _matches_resume_keywords(message: str) -> bool:
+    compact = re.sub(r"\s+", "", str(message or ""))
+    if not compact:
+        return False
+    return any(keyword in compact for keyword in RESUME_CONFIRMATION_KEYWORDS)
+
+
+def _flow_has_resumable_fields(flow: dict[str, Any]) -> bool:
+    """判断 flow 是否还有可恢复的业务字段（至少有 1 个非空字段）。"""
+    fields = flow.get("fields")
+    if not isinstance(fields, dict):
+        return False
+    return any(
+        str(value or "").strip()
+        for value in fields.values()
+    )
--- a/server/src/app/services/steward_intent_agent.py
+++ b/server/src/app/services/steward_intent_agent.py
@@ -103,8 +103,17 @@ class StewardIntentAgent:
                    "employee_grade",
                    "employee_no",
                    "client_timezone_offset_minutes",
+                    "recent_history",
                }
            },
+            "recent_history": [
+                {
+                    "role": str(item.get("role") or "").strip(),
+                    "content": str(item.get("content") or "").strip(),
+                }
+                for item in (request.context_json.get("recent_history") or [])
+                if isinstance(item, dict) and str(item.get("content") or "").strip()
+            ],
            "attachments": [
                {
                    "index": index + 1,
@@ -134,6 +143,11 @@ class StewardIntentAgent:
                    "每个 task 必须输出 requested_action：用户只是要求整理/发起但未说保存或提交时为 preview；"
                    "用户说保存草稿、先保存、存草稿时为 save_draft；用户说直接提交、提交申请、确认提交时为 submit。"
                    "对于查询类任务(如查询差旅标准),requested_action 固定为 preview。"
+                    "recent_history 是本会话最近 10 轮对话（role 为 user 或 assistant）。"
+                    "当用户说“再提交”“继续”“重新提交”“重新申请”等确认类话术时，"
+                    "必须结合 recent_history 里最近一次提到的出差/报销申请来理解用户意图，"
+                    "复用该申请的 ontology_fields 重新生成 task，而不是把确认话术当作孤立的模糊输入。"
+                    "如果 recent_history 为空或无法关联到具体申请，才按当前 message 字面理解。"
                    "相对日期必须以 base_date 为准转换为明确日期。"
                    "thinking_events 只能是面向用户的过程摘要，不能暴露内部推理链。"
                    "如果用户输入与出差、费用、报销、申请、差旅标准等财务事项完全无关"