feat: QMT Bridge 设为主数据源，新增指数日K支持及数据源文档

- QmtBridgeSource: provides 增加 index_daily，新增 fetch_index_daily 方法
- task_kline_index: 优先级改为 qmt_bridge → mairui → sina 三级降级
- task_kline_5min: 优先用 qmt_bridge，不可用时降级 mairui
- task_kline_daily: 优先级加入 qmt_bridge（首位）
- config: 新增 qmt_bridge_url 配置项
- registry: qmt_bridge 注册信息同步更新
- docs: 新增 DATASETS_AND_SOURCES.md，完整说明数据集与数据源依赖关系
- AGENTS.md: 同步更新指数数据源描述

app/core/config.py

@@ -62,6 +62,9 @@ class Settings(BaseSettings):
     pg_password: str = "market_sync"
     pg_db_name: str = "market_data"
 
+    # QMT Bridge
+    qmt_bridge_url: str = "http://127.0.0.1:8610"
+
     # Trading calendar
     trading_holidays: str = ""
 

app/core/datasource/registry.py

@@ -23,6 +23,16 @@ logger = get_logger("datasource_health")
 
 
 _DATASOURCE_SEED: list[tuple[str, dict, str]] = [
+    (
+        "datasource_qmt_bridge",
+        {
+            "name": "QMT Bridge（本地行情桥）",
+            "provides": ["kline_daily", "kline_5min", "index_daily"],
+            "requiresCredential": False,
+            "note": "本地 QMT HTTP 桥，日K + 5分钟K + 指数日K 主源",
+        },
+        "日 K + 5 分钟 K + 指数日 K 主源（替代 mairui）",
+    ),
     (
         "datasource_xinlang",
         {
@@ -248,10 +258,12 @@ def build_default_registry() -> None:
     from app.sources.baostock import BaostockSource
     from app.sources.xueqiu import XueqiuSource
     from app.sources.mairui import MairuiSource
+    from app.sources.qmt_bridge import QmtBridgeSource
 
     registry.register(SinaSource())
     registry.register(BaostockSource())
     registry.register(MairuiSource())
+    registry.register(QmtBridgeSource())
     if settings.xueqiu_token:
         registry.register(XueqiuSource())
     else:

app/core/sync/registry.py

@@ -53,7 +53,7 @@ SYNC_DEFINITIONS: list[dict[str, Any]] = [
         "storage_uri": "PG market_data.kline_index + indices",
         "storage_layer": "pg",
         "management_role": "原始源",
-        "source": "新浪指数日K",
+        "source": "QMT Bridge（主）→ 麦蕊 → 新浪 逐级 fallback",
         "sync_script": "app.tasks.task_kline_index:run",
         "dependency_ids": [],
         "sort_order": 30,