feat(wrapped): 新增年度总结接口与卡片 #1（赛博作息表）

- 新增 /api/wrapped/annual（year/account/refresh），统计在 worker thread 中执行

- 实现卡片#1：按 周×小时 聚合消息量，默认过滤 biz_message*.db

- 增加 _wrapped/cache JSON 缓存（global_<year>_upto_1.json），refresh 支持强制重算

src/wechat_decrypt_tool/wrapped/storage.py

@@ -0,0 +1,33 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+
+def wrapped_account_dir(account_dir: Path) -> Path:
+    """Return the per-account wrapped working directory.
+
+    We keep all wrapped artifacts under `<account>/_wrapped` so they travel
+    with the decrypted databases and are easy to inspect/backup.
+    """
+
+    return account_dir / "_wrapped"
+
+
+def wrapped_cache_dir(account_dir: Path) -> Path:
+    d = wrapped_account_dir(account_dir) / "cache"
+    d.mkdir(parents=True, exist_ok=True)
+    return d
+
+
+def wrapped_cache_path(
+    *,
+    account_dir: Path,
+    scope: str,
+    year: int,
+    implemented_upto: int,
+    options_tag: str | None = None,
+) -> Path:
+    # NOTE: Keep the filename stable and versioned by "implemented_upto" so when we
+    # add more cards later we don't accidentally serve a partial cache.
+    suffix = f"_{options_tag}" if options_tag else ""
+    return wrapped_cache_dir(account_dir) / f"{scope}_{year}_upto_{implemented_upto}{suffix}.json"