feat: 日报多来源入库（news_event.sources 列，JSON 数组，主源居首）

- EventRow 新增 sources 字段；init_schema 幂等 ALTER 补列（MariaDB）
- save_report 写入 sources JSON；_article_sources_full 完整来源列表
- source 字段保持 ≤3 拼接兼容；新增多源完整列表测试
- 已部署 pi5：sources 列写入验证通过（单源数组）；完整多源待新数据

tests/test_report_db.py

@@ -179,17 +179,31 @@ class TestBuildReportData:
         assert r.events[0].sentiment is None
 
     def test_multi_source_label(self) -> None:
-        """去重合并后的多来源 → source 拼接展示（Reuters, CNBC）。"""
+        """去重合并后的多来源 → source 拼接展示（Reuters, CNBC）+ sources 完整列表。"""
         now = datetime(2026, 8, 4, 8, 0, 0)
         ev = _fake_high_event("多来源事件", 5, source_id="reuters",
                               url="https://reuters.com/news/9")
-        # 模拟 M3 去重合并：source_ids 含两个来源
+        # 模拟 M3 去重合并：source_ids 含两个来源（主源 reuters 居首）
         ev["article"]["source_ids"] = ["reuters", "cnbc"]
         r = _build_report_data(now, {}, [ev], Counter(), Counter(), Counter(),
                                Counter(), "")
         assert r.events[0].source == "Reuters, CNBC"
+        assert r.events[0].sources == ["Reuters", "CNBC"]  # 主源居首
         assert r.events[0].url == "https://reuters.com/news/9"
 
+    def test_multi_source_full_list(self) -> None:
+        """超过 3 个来源：source 截前 3，sources 存完整列表。"""
+        now = datetime(2026, 8, 4, 8, 0, 0)
+        ev = _fake_high_event("四来源事件", 5, source_id="barrons",
+                              url="https://barrons.com/news/1")
+        ev["article"]["source_ids"] = ["barrons", "cnbc", "reuters", "ft"]
+        r = _build_report_data(now, {}, [ev], Counter(), Counter(), Counter(),
+                               Counter(), "")
+        assert r.events[0].source == "Barron's, CNBC, Reuters"       # 前 3 拼接
+        assert r.events[0].sources == [                               # 完整 4 个
+            "Barron's", "CNBC", "Reuters", "Financial Times",
+        ]
+
     def test_single_source_falls_back(self) -> None:
         """source_ids 为空/单一时回退单源逻辑（不拼接）。"""
         now = datetime(2026, 8, 4, 8, 0, 0)
@@ -199,3 +213,4 @@ class TestBuildReportData:
         r = _build_report_data(now, {}, [ev], Counter(), Counter(), Counter(),
                                Counter(), "")
         assert r.events[0].source == "InvestingLive"
+        assert r.events[0].sources == ["InvestingLive"]