feat(p3): add discovery, telegram notifications, and one-click favorites

Implement WBI video search with legacy fallback, classification scoring, candidate pool, permanent seen-aid dedupe, blacklist filtering, and batched Telegram notifications. Add write client for fav deal/sort, target-folder selection, insertion position calculation, read-back verification, fav_action locking, retry on failure, ignore and blacklist actions. Wire discovery, candidate cleanup, Telegram long polling, and new discover/candidates CLI commands into the scheduler. Add migration v3 for candidate duration and index stats.

reaction_board/fav_position.py

@@ -0,0 +1,82 @@
+# -*- coding: utf-8 -*-
+"""新视频在收藏夹中的插入位置计算（纯函数）。"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import Mapping, Sequence
+
+
+@dataclass(frozen=True)
+class VideoMeta:
+    up_mid: int | None
+    pubdate: int
+
+
+@dataclass(frozen=True)
+class InsertionPlan:
+    target_position: int
+    moves: tuple[tuple[int, int], ...]  # (pred_aid, moved_aid)
+
+    @property
+    def needs_head_move(self) -> bool:
+        return len(self.moves) == 2
+
+
+def plan_insertion(
+    current_ids: Sequence[int],
+    new_aid: int,
+    metadata: Mapping[int, VideoMeta],
+    new_meta: VideoMeta,
+) -> InsertionPlan:
+    """按“同 UP 连续、组间按最早投稿倒序”计算插入点。
+
+    ``current_ids`` 可以包含 ``new_aid``（通常在末尾），函数会先排除它。
+    """
+    ordered = [int(aid) for aid in current_ids if int(aid) != int(new_aid)]
+    if not ordered:
+        return InsertionPlan(target_position=1, moves=())
+
+    groups: list[dict] = []
+    for index, aid in enumerate(ordered):
+        meta = metadata.get(aid)
+        up_mid = meta.up_mid if meta else None
+        if up_mid is not None and groups and groups[-1]["up_mid"] == up_mid:
+            groups[-1]["aids"].append(aid)
+        else:
+            groups.append({"up_mid": up_mid, "aids": [aid], "start": index})
+
+    for group in groups:
+        keys = [
+            metadata[aid].pubdate
+            for aid in group["aids"]
+            if aid in metadata and metadata[aid].pubdate > 0
+        ]
+        group["key"] = min(keys) if keys else 0
+
+    insert_index: int | None = None
+    if new_meta.up_mid is not None:
+        for group in groups:
+            if group["up_mid"] == new_meta.up_mid:
+                insert_index = group["start"]
+                break
+    if insert_index is None:
+        for group in groups:
+            if group["key"] < new_meta.pubdate:
+                insert_index = group["start"]
+                break
+    if insert_index is None:
+        insert_index = len(ordered)
+
+    target_position = insert_index + 1
+    if insert_index == 0:
+        first = ordered[0]
+        return InsertionPlan(
+            target_position=1,
+            moves=((first, int(new_aid)), (int(new_aid), first)),
+        )
+    predecessor = ordered[insert_index - 1]
+    return InsertionPlan(
+        target_position=target_position,
+        moves=((predecessor, int(new_aid)),),
+    )