feat(HEL-382): 搭建 datahub 底座和盘后正式数据链路

新增独立 xiaobai-datahub 服务（SQLite WAL、Tushare 盘后发布、/v1 契约和管理后台），不改现站页面与数据链路。

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>

xiaobai-datahub/datahub/codes.py

@@ -0,0 +1,26 @@
+from __future__ import annotations
+
+from datahub.db import HubDB
+
+
+def resolve_code(db: HubDB, raw: str) -> str | None:
+    text = str(raw or "").strip().upper()
+    if not text:
+        return None
+    if "." in text:
+        row = db.fetchone("SELECT ts_code FROM stock_master WHERE ts_code = ?", (text,))
+        if row:
+            return row["ts_code"]
+        # indices are not always in stock_master
+        return text
+    matches = db.fetchall(
+        "SELECT ts_code FROM stock_master WHERE symbol = ? OR ts_code LIKE ?",
+        (text, f"{text}.%"),
+    )
+    if len(matches) == 1:
+        return matches[0]["ts_code"]
+    if len(matches) > 1:
+        return None
+    # unique exchange guess for 6-digit codes
+    suffix = "SH" if text.startswith("6") or text.startswith("9") else "SZ" if text.startswith(("0", "3")) else "BJ"
+    return f"{text}.{suffix}"