Add HeXi bot codebase: custom plugins, web frontends, tests

- hexi core: message handling, rate limiting, cooldown, plugin manager
- Custom plugins: BF stats, daily check-in, quotes, persona cards, etc.
- Community plugins vendored under hexi/plugins with local fixes
- Web admin frontends (learning-chat, persona-admin), unified hexi/web
- Tests for rate_limit/cooldown/memes/persona; poetry.lock

Co-Authored-By: Claude <noreply@anthropic.com>

hexi/plugins/nonebot_plugin_video_analysis/handlers/universal.py

@@ -0,0 +1,40 @@
+"""通用平台视频解析编排层 — B站 / YouTube / Twitter 等"""
+
+from pathlib import Path
+from typing import Optional
+
+from nonebot import logger
+from nonebot_plugin_alconna import UniMessage
+
+from ..fetchers.video_downloader import download_video
+from .sender import PendingMedia, _as_paths
+
+
+async def handle_universal(
+    url: str,
+    is_private: bool,
+    plan: str | None = None,
+) -> tuple[Optional[PendingMedia], Optional[str]]:
+    """
+    下载通用平台视频 → 打包待发送媒体（上传/发送由 sender 多级处理）
+
+    Returns:
+        (PendingMedia, public_url) — None 表示下载失败
+    """
+    video_file = await download_video(url)
+    if not video_file:
+        await UniMessage.text("视频下载失败。").send()
+        return None, None
+
+    logger.info(f"文件路径：{video_file}")
+
+    return (
+        PendingMedia(
+            files=_as_paths(video_file),
+            image_post=False,
+            is_private=is_private,
+            plan=plan,
+            title="title",
+        ),
+        None,
+    )