feat: add database backup and restore in system settings

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

packages/db/backup.py

@@ -0,0 +1,87 @@
+"""SQLite 在线备份与恢复。"""
+
+from __future__ import annotations
+
+import re
+import sqlite3
+from datetime import datetime
+from pathlib import Path
+from zoneinfo import ZoneInfo
+
+_BACKUP_NAME_RE = re.compile(r"^market_intel_\d{8}_\d{6}\.db$")
+
+
+def _now_stamp(tz: str = "Asia/Shanghai") -> str:
+    return datetime.now(ZoneInfo(tz)).strftime("%Y%m%d_%H%M%S")
+
+
+def ensure_backup_dir(path: Path) -> Path:
+    path.mkdir(parents=True, exist_ok=True)
+    return path
+
+
+def is_valid_backup_name(name: str) -> bool:
+    return bool(_BACKUP_NAME_RE.fullmatch(name))
+
+
+def resolve_backup_file(backup_dir: Path, name: str) -> Path:
+    if not is_valid_backup_name(name):
+        raise ValueError("invalid backup filename")
+    path = (backup_dir / name).resolve()
+    root = backup_dir.resolve()
+    if not str(path).startswith(str(root)):
+        raise ValueError("invalid backup path")
+    if not path.is_file():
+        raise FileNotFoundError(name)
+    return path
+
+
+def backup_db(db_path: Path, backup_dir: Path, tz: str = "Asia/Shanghai") -> Path:
+    ensure_backup_dir(backup_dir)
+    if not db_path.is_file():
+        raise FileNotFoundError(f"database not found: {db_path}")
+
+    dest = backup_dir / f"market_intel_{_now_stamp(tz)}.db"
+    src = sqlite3.connect(str(db_path))
+    try:
+        dst = sqlite3.connect(str(dest))
+        try:
+            src.backup(dst)
+        finally:
+            dst.close()
+    finally:
+        src.close()
+    return dest
+
+
+def restore_db(backup_path: Path, db_path: Path) -> None:
+    if not backup_path.is_file():
+        raise FileNotFoundError(f"backup not found: {backup_path}")
+
+    src = sqlite3.connect(str(backup_path))
+    try:
+        dst = sqlite3.connect(str(db_path))
+        try:
+            src.backup(dst)
+        finally:
+            dst.close()
+    finally:
+        src.close()
+
+
+def list_backups(backup_dir: Path) -> list[dict]:
+    if not backup_dir.is_dir():
+        return []
+    items: list[dict] = []
+    for p in sorted(backup_dir.glob("market_intel_*.db"), reverse=True):
+        if not p.is_file() or not is_valid_backup_name(p.name):
+            continue
+        st = p.stat()
+        items.append(
+            {
+                "name": p.name,
+                "size_bytes": st.st_size,
+                "modified_ms": int(st.st_mtime * 1000),
+            }
+        )
+    return items