feat: 增强差旅报销审核流程与票据智能推理

优化本体解析和编排器的差旅场景处理能力，完善报销单草稿
保存和费用明细同步逻辑，前端报销创建页面增加行程推理和
票据审核交互，新增助手会话快照工具函数，补充单元测试。

server/tests/test_expense_claim_service.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from datetime import UTC, date, datetime
+from datetime import UTC, date, datetime, timedelta
 from decimal import Decimal
 
 import pytest
@@ -69,6 +69,10 @@ def build_session() -> Session:
     return session_factory()
 
 
+def _count_claims(db: Session) -> int:
+    return int(db.query(ExpenseClaim).count())
+
+
 def test_validate_claim_for_submission_allows_office_claim_without_location() -> None:
     service = ExpenseClaimService.__new__(ExpenseClaimService)
     claim = build_claim(expense_type="office", location="待补充")
@@ -99,6 +103,112 @@ def test_validate_claim_for_submission_still_requires_location_for_travel_claim(
     assert any("缺少地点" in item for item in issues)
 
 
+def test_save_or_submit_preview_does_not_create_claim_without_explicit_action() -> None:
+    user_id = "preview-only@example.com"
+    message = "业务发生时间:2026-03-04，打车去客户现场，交通费32元，请帮我看看怎么报"
+
+    with build_session() as db:
+        employee = Employee(
+            employee_no="E5100",
+            name="预览员工",
+            email=user_id,
+        )
+        db.add(employee)
+        db.commit()
+        ontology = SemanticOntologyService(db).parse(
+            OntologyParseRequest(
+                query=message,
+                user_id=user_id,
+            )
+        )
+        before_count = _count_claims(db)
+
+        result = ExpenseClaimService(db).save_or_submit_from_ontology(
+            run_id=ontology.run_id,
+            user_id=user_id,
+            message=message,
+            ontology=ontology,
+            context_json={
+                "name": "预览员工",
+                "user_input_text": message,
+            },
+        )
+
+        assert result["preview_only"] is True
+        assert result["status"] == "preview"
+        assert "尚未保存为草稿" in result["message"]
+        assert _count_claims(db) == before_count
+
+
+def test_save_or_submit_persists_claim_only_after_save_draft_action() -> None:
+    user_id = "save-draft-explicit@example.com"
+    message = "业务发生时间:2026-03-04，打车去客户现场，交通费32元，请帮我看看怎么报"
+
+    with build_session() as db:
+        employee = Employee(
+            employee_no="E5101",
+            name="保存员工",
+            email=user_id,
+        )
+        db.add(employee)
+        db.commit()
+        ontology = SemanticOntologyService(db).parse(
+            OntologyParseRequest(
+                query=message,
+                user_id=user_id,
+            )
+        )
+        before_count = _count_claims(db)
+
+        result = ExpenseClaimService(db).save_or_submit_from_ontology(
+            run_id=ontology.run_id,
+            user_id=user_id,
+            message=message,
+            ontology=ontology,
+            context_json={
+                "name": "保存员工",
+                "user_input_text": message,
+                "review_action": "save_draft",
+            },
+        )
+
+        assert result["draft_only"] is True
+        assert result["claim_id"]
+        assert result["status"] == "draft"
+        assert _count_claims(db) == before_count + 1
+
+
+def test_unsaved_conversation_expires_after_retention_but_saved_conversation_stays() -> None:
+    with build_session() as db:
+        service = AgentConversationService(db)
+        unsaved = service.get_or_create_conversation(
+            conversation_id="conv-unsaved-expire",
+            user_id="expire@example.com",
+            source="user_message",
+            context_json={"session_type": "expense"},
+        )
+        saved = service.get_or_create_conversation(
+            conversation_id="conv-saved-keep",
+            user_id="expire@example.com",
+            source="user_message",
+            context_json={
+                "session_type": "expense",
+                "draft_claim_id": "claim-saved",
+            },
+        )
+        old_time = datetime.now(UTC) - timedelta(days=4)
+        unsaved.updated_at = old_time
+        saved.updated_at = old_time
+        db.add_all([unsaved, saved])
+        db.commit()
+
+        deleted_count = service.prune_expired_conversations(retention_days=3)
+
+        assert deleted_count == 1
+        assert service.get_conversation("conv-unsaved-expire") is None
+        assert service.get_conversation("conv-saved-keep") is not None
+
+
 def test_resolve_expense_type_maps_office_supplies_review_value_to_office() -> None:
     expense_type = ExpenseClaimService._resolve_expense_type(
         [],
@@ -574,6 +684,83 @@ def test_upsert_travel_draft_uses_ticket_item_types_and_auto_allowance() -> None
             )
 
 
+def test_sync_travel_claim_adds_allowance_from_manual_ticket_dates() -> None:
+    with build_session() as db:
+        employee = Employee(
+            employee_no="E5011",
+            name="手工差旅员工",
+            email="manual-travel-allowance@example.com",
+            grade="P4",
+        )
+        db.add(employee)
+        db.flush()
+
+        claim = build_claim(expense_type="travel", location="北京")
+        claim.employee_id = employee.id
+        claim.employee_name = employee.name
+        claim.items[0].item_date = date(2026, 5, 13)
+        claim.items[0].item_type = "train_ticket"
+        claim.items[0].item_reason = "广州南-北京南"
+        claim.items[0].item_location = "北京"
+        claim.items[0].item_amount = Decimal("354.00")
+        claim.items.append(
+            ExpenseClaimItem(
+                claim_id=claim.id,
+                item_date=date(2026, 5, 15),
+                item_type="train_ticket",
+                item_reason="北京南-广州南",
+                item_location="北京",
+                item_amount=Decimal("354.00"),
+                invoice_id="return-train.png",
+            )
+        )
+        db.add(claim)
+        db.commit()
+
+        service = ExpenseClaimService(db)
+        service._sync_claim_from_items(claim)
+        db.commit()
+        db.refresh(claim)
+
+        allowance_item = next(item for item in claim.items if item.item_type == "travel_allowance")
+        assert allowance_item.item_amount == Decimal("300.00")
+        assert "3天" in allowance_item.item_reason
+        assert allowance_item.invoice_id is None
+        assert claim.amount == Decimal("1008.00")
+
+
+def test_update_claim_item_allows_placeholder_date_reason_and_amount() -> None:
+    current_user = CurrentUserContext(
+        username="emp-1",
+        name="张三",
+        role_codes=[],
+        is_admin=False,
+    )
+
+    with build_session() as db:
+        claim = build_claim(expense_type="office", location="深圳")
+        db.add(claim)
+        db.commit()
+
+        updated = ExpenseClaimService(db).update_claim_item(
+            claim_id=claim.id,
+            item_id=claim.items[0].id,
+            payload=ExpenseClaimItemUpdate(
+                item_reason="",
+                item_location="",
+                item_amount=Decimal("0.00"),
+            ),
+            current_user=current_user,
+        )
+
+        assert updated is not None
+        db.refresh(claim)
+        assert claim.items[0].item_date == date(2026, 5, 13)
+        assert claim.items[0].item_reason == ""
+        assert claim.items[0].item_location == ""
+        assert claim.items[0].item_amount == Decimal("0.00")
+
+
 def test_upsert_draft_from_ontology_updates_returned_claim_and_preserves_return_events() -> None:
     user_id = "returned-owner@example.com"
     return_flag = {
@@ -989,6 +1176,9 @@ def test_upload_train_ticket_attachment_backfills_item_amount(monkeypatch, tmp_p
 
         assert updated is not None
         assert updated["item_amount"] == Decimal("354.00")
+        assert updated["item_date"] == "2026-02-20"
+        assert updated["item_type"] == "train_ticket"
+        assert updated["item_reason"] == "广州南-北京南"
         assert updated["claim_amount"] == Decimal("354.00")
         db.refresh(claim)
         assert claim.items[0].item_amount == Decimal("354.00")
@@ -1018,6 +1208,86 @@ def test_upload_train_ticket_attachment_backfills_item_amount(monkeypatch, tmp_p
         assert not any("用途字段" in point for point in uploaded_meta["analysis"]["points"])
 
 
+def test_upload_hotel_attachment_audits_date_like_amount(monkeypatch, tmp_path) -> None:
+    current_user = CurrentUserContext(
+        username="emp-1",
+        name="张三",
+        role_codes=[],
+        is_admin=False,
+    )
+
+    def fake_recognize(
+        self,
+        files: list[tuple[str, bytes, str | None]],
+    ) -> OcrRecognizeBatchRead:
+        return OcrRecognizeBatchRead(
+            total_file_count=1,
+            success_count=1,
+            documents=[
+                OcrRecognizeDocumentRead(
+                    filename="hotel-invoice.png",
+                    media_type="image/png",
+                    text="北京中心酒店 总费用是828元 入住日期 2026-02-20 离店日期 2026-02-21",
+                    summary="酒店住宿票据，住宿总费用 828 元。",
+                    avg_score=0.96,
+                    line_count=1,
+                    page_count=1,
+                    document_type="hotel_invoice",
+                    document_type_label="酒店住宿票据",
+                    scene_code="hotel",
+                    scene_label="住宿票据",
+                    document_fields=[
+                        {"key": "amount", "label": "金额", "value": "2026元"},
+                        {"key": "hotel_name", "label": "酒店", "value": "北京中心酒店"},
+                        {"key": "check_in", "label": "入住日期", "value": "2026-02-20"},
+                        {"key": "check_out", "label": "离店日期", "value": "2026-02-21"},
+                    ],
+                )
+            ],
+        )
+
+    monkeypatch.setattr(OcrService, "recognize_files", fake_recognize)
+    monkeypatch.setattr(ExpenseClaimService, "_get_attachment_storage_root", lambda self: tmp_path)
+
+    with build_session() as db:
+        claim = build_claim(expense_type="hotel", location="北京")
+        claim.amount = Decimal("0.00")
+        claim.invoice_count = 0
+        claim.items[0].item_type = "hotel"
+        claim.items[0].item_reason = ""
+        claim.items[0].item_amount = Decimal("0.00")
+        claim.items[0].invoice_id = None
+        db.add(claim)
+        db.commit()
+
+        service = ExpenseClaimService(db)
+        updated = service.upload_claim_item_attachment(
+            claim_id=claim.id,
+            item_id=claim.items[0].id,
+            filename="hotel-invoice.png",
+            content=b"fake-image-bytes",
+            media_type="image/png",
+            current_user=current_user,
+        )
+
+        assert updated is not None
+        assert updated["item_type"] == "hotel_ticket"
+        assert updated["item_amount"] == Decimal("828.00")
+        assert updated["claim_amount"] == Decimal("828.00")
+        db.refresh(claim)
+        assert claim.items[0].item_amount == Decimal("828.00")
+        assert claim.amount == Decimal("828.00")
+        uploaded_meta = service.get_claim_item_attachment_meta(
+            claim_id=claim.id,
+            item_id=claim.items[0].id,
+            current_user=current_user,
+        )
+        assert uploaded_meta is not None
+        assert uploaded_meta["analysis"]["severity"] == "medium"
+        assert any("费用核算" in point and "828.00 元" in point for point in uploaded_meta["analysis"]["points"])
+        assert not any("2026.00 元与报销金额" in point for point in uploaded_meta["analysis"]["points"])
+
+
 def test_attachment_analysis_does_not_compare_business_purpose_with_ticket_scene() -> None:
     with build_session() as db:
         claim = build_claim(expense_type="travel", location="上海")
@@ -1053,7 +1323,7 @@ def test_attachment_analysis_does_not_compare_business_purpose_with_ticket_scene
 
         assert analysis["severity"] == "medium"
         assert not any("用途字段" in point for point in analysis["points"])
-        assert any("行程说明" in point and "始发地-目的地" in point for point in analysis["points"])
+        assert any("行程说明" in point and "起始地-目的地" in point for point in analysis["points"])
 
 
 def test_attachment_risk_flag_message_uses_specific_points(monkeypatch, tmp_path) -> None: