feat(server): 报销单输出工号/邮箱并扩展申请人邮箱前缀匹配

- ExpenseClaimRead 新增 employee_no/employee_email 字段，ExpenseClaim 模型补对应只读属性
- expense_claim_access_policy 在姓名匹配未果时，按 candidate@% 邮箱前缀匹配 Employee.email，命中唯一记录即返回
- test_backend_pagination/test_expense_claim_service 补充工号/邮箱字段断言与邮箱前缀匹配用例
- 更新公司通信费报销规则表

server/tests/test_backend_pagination.py

@@ -105,6 +105,8 @@ def test_expense_claims_support_page_envelope_and_keep_legacy_list() -> None:
     assert payload["total_pages"] == 2
     assert payload["has_next"] is True
     assert payload["has_previous"] is False
+    assert payload["items"][0]["employee_no"] == "E-PAGE"
+    assert payload["items"][0]["employee_email"] == "page-user@example.com"
 
 
 def test_employee_directory_supports_backend_pagination() -> None:

server/tests/test_expense_claim_service.py

@@ -4301,6 +4301,50 @@ def test_list_claims_scopes_to_current_user_id_even_when_names_duplicate() -> No
         assert claims[0].claim_no == "EXP-DUP-001"
 
 
+def test_list_claims_resolves_short_username_to_unique_employee_email_prefix() -> None:
+    current_user = CurrentUserContext(
+        username="caoxiaozhu",
+        name="caoxiaozhu",
+        role_codes=["employee"],
+        is_admin=False,
+    )
+
+    with build_session() as db:
+        employee = Employee(
+            employee_no="E90919",
+            name="曹笑竹",
+            email="caoxiaozhu@xf.com",
+        )
+        db.add(employee)
+        db.flush()
+        db.add(
+            ExpenseClaim(
+                claim_no="AP-SHORT-USERNAME-001",
+                employee_id=employee.id,
+                employee_name=employee.name,
+                department_name="研发部",
+                project_code="PRJ-APP",
+                expense_type="travel_application",
+                reason="客户现场实施",
+                location="北京",
+                amount=Decimal("1600.00"),
+                currency="CNY",
+                invoice_count=0,
+                occurred_at=datetime(2026, 6, 23, 9, 0, tzinfo=UTC),
+                submitted_at=datetime(2026, 6, 23, 10, 0, tzinfo=UTC),
+                status="approved",
+                approval_stage=APPROVAL_DONE_STAGE,
+                risk_flags_json=[],
+            )
+        )
+        db.commit()
+
+        claims = ExpenseClaimService(db).list_claims(current_user)
+
+        assert len(claims) == 1
+        assert claims[0].claim_no == "AP-SHORT-USERNAME-001"
+
+
 def test_list_claims_limits_finance_to_personal_records() -> None:
     current_user = CurrentUserContext(
         username="finance@example.com",