Use Sina-only market K-lines and editable admin login synced to .env.

Market page uses Sina for quotes and bars with an auto-follow toggle and incremental chart updates while panning. Settings lets users change username and password, persisting to the database and .env.

Co-authored-by: Cursor <cursoragent@cursor.com>

env_file.py

@@ -0,0 +1,60 @@
+# Copyright (c) 2025-2026 马建军. All rights reserved.
+# 专有软件 — 未经授权禁止复制、传播、转售。
+# 严禁用于：带单/代客理财、向他人推荐期货品种或买卖建议、融资配资等业务。
+# 详见 LICENSE.zh-CN.txt 与 docs/软件购买与使用协议.md
+
+"""读写项目根目录 .env 文件（更新指定键，保留其余行）。"""
+from __future__ import annotations
+
+import os
+import re
+
+ENV_PATH = os.path.join(os.path.dirname(os.path.abspath(__file__)), ".env")
+_KEY_RE = re.compile(r"^([A-Za-z_][A-Za-z0-9_]*)\s*=")
+
+
+def env_file_path(path: str | None = None) -> str:
+    return path or ENV_PATH
+
+
+def _quote_env_value(value: str) -> str:
+    if value == "":
+        return '""'
+    if re.search(r'[\s#"\'\\=]', value):
+        escaped = value.replace("\\", "\\\\").replace('"', '\\"')
+        return f'"{escaped}"'
+    return value
+
+
+def update_env_vars(updates: dict[str, str], path: str | None = None) -> None:
+    """更新或追加 KEY=value，不改动注释与其他配置项。"""
+    if not updates:
+        return
+    env_path = env_file_path(path)
+    lines: list[str] = []
+    if os.path.isfile(env_path):
+        with open(env_path, encoding="utf-8") as f:
+            lines = f.read().splitlines()
+
+    seen: set[str] = set()
+    out: list[str] = []
+    for line in lines:
+        stripped = line.strip()
+        if not stripped or stripped.startswith("#"):
+            out.append(line)
+            continue
+        m = _KEY_RE.match(stripped)
+        if m and m.group(1) in updates:
+            key = m.group(1)
+            out.append(f"{key}={_quote_env_value(updates[key])}")
+            seen.add(key)
+        else:
+            out.append(line)
+
+    for key, val in updates.items():
+        if key not in seen:
+            out.append(f"{key}={_quote_env_value(val)}")
+
+    with open(env_path, "w", encoding="utf-8", newline="\n") as f:
+        if out:
+            f.write("\n".join(out) + "\n")