feat(p1): add daily snapshots and fan tracking

Implement P1: seven-metric view snapshots, relation/stat fan snapshots, failure placeholders, resume by daily completion markers, Cookie login warnings, daily SQLite backups, Shanghai daily scheduling, and CLI snapshot/auth-check commands. Real read-only run captured 795/795 videos successfully over 1124s with a verified daily backup.

reaction_board/bilibili/models.py

@@ -85,3 +85,83 @@ class InfosResult:
     requested: tuple[int, ...]
     items: dict[int, FavResource]
     missing: tuple[int, ...]
+
+
+@dataclass(frozen=True)
+class ViewStat:
+    """``x/web-interface/view`` 的七项统计。"""
+
+    aid: int
+    bvid: str | None
+    title: str
+    view: int
+    like: int
+    favorite: int
+    coin: int
+    share: int
+    reply: int
+    danmaku: int
+
+    def metrics(self) -> dict[str, int]:
+        return {
+            "view": self.view,
+            "like": self.like,
+            "favorite": self.favorite,
+            "coin": self.coin,
+            "share": self.share,
+            "reply": self.reply,
+            "danmaku": self.danmaku,
+        }
+
+    @classmethod
+    def from_api(cls, item: Mapping[str, Any]) -> "ViewStat":
+        aid = item.get("aid")
+        if isinstance(aid, bool) or not isinstance(aid, int):
+            raise ValueError("view data.aid 不是整数")
+        stat = item.get("stat")
+        if not isinstance(stat, Mapping):
+            raise ValueError("view data.stat 不是对象")
+        metrics: dict[str, int] = {}
+        for key in ("view", "like", "favorite", "coin", "share", "reply", "danmaku"):
+            value = stat.get(key)
+            if isinstance(value, bool) or not isinstance(value, int) or value < 0:
+                raise ValueError(f"view stat.{key} 不是非负整数")
+            metrics[key] = value
+        bvid = item.get("bvid")
+        if not isinstance(bvid, str) or not bvid:
+            bvid = None
+        return cls(
+            aid=aid,
+            bvid=bvid,
+            title=str(item.get("title") or ""),
+            **metrics,
+        )
+
+
+@dataclass(frozen=True)
+class FanStat:
+    mid: int
+    follower: int
+    following: int
+
+    @classmethod
+    def from_api(cls, item: Mapping[str, Any]) -> "FanStat":
+        mid = item.get("mid")
+        follower = item.get("follower")
+        following = item.get("following", 0)
+        if isinstance(mid, bool) or not isinstance(mid, int):
+            raise ValueError("relation/stat data.mid 不是整数")
+        if isinstance(follower, bool) or not isinstance(follower, int) or follower < 0:
+            raise ValueError("relation/stat data.follower 不是非负整数")
+        if isinstance(following, bool) or not isinstance(following, int) or following < 0:
+            raise ValueError("relation/stat data.following 不是非负整数")
+        return cls(mid=mid, follower=follower, following=following)
+
+
+@dataclass(frozen=True)
+class LoginState:
+    is_login: bool
+    mid: int | None
+    uname: str | None
+    code: int
+    message: str