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_group_daily_analysis/templates.py

@@ -0,0 +1,34 @@
+"""模板目录的本地访问（NoneBot 版，避免引入 AstrBot 消息组件）。"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+_TEMPLATES_DIR = (
+    Path(__file__).resolve().parent
+    / "core"
+    / "infrastructure"
+    / "reporting"
+    / "templates"
+)
+_ASSETS_DIR = Path(__file__).resolve().parent / "assets"
+
+
+def list_templates() -> list[str]:
+    """按字典序返回可用模板名，与设置模板的 1..N 编号一致。"""
+    if not _TEMPLATES_DIR.exists():
+        return []
+    return sorted(
+        d.name
+        for d in _TEMPLATES_DIR.iterdir()
+        if d.is_dir() and not d.name.startswith("__")
+    )
+
+
+def template_exists(template: str) -> bool:
+    return (_TEMPLATES_DIR / template).is_dir()
+
+
+def preview_image(template: str) -> Path | None:
+    p = _ASSETS_DIR / f"{template}-demo.jpg"
+    return p if p.exists() else None