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>

plugin_template/nonebot_plugin_template/repository.py

@@ -0,0 +1,37 @@
+"""Model 层的数据访问：唯一读写入口(此处用 JSON 文件示例)。"""
+
+from __future__ import annotations
+
+import json
+import os
+from pathlib import Path
+
+# Runtime data belongs under hexi/data, not beside importable plugin code.
+_DATA_DIR = Path(__file__).resolve().parents[2] / "data" / "nonebot_plugin_template"
+_STORE = _DATA_DIR / "store.json"
+
+
+def _load() -> dict:
+    if _STORE.exists():
+        try:
+            return json.loads(_STORE.read_text("utf-8"))
+        except json.JSONDecodeError:
+            return {}
+    return {}
+
+
+def _save(data: dict) -> None:
+    _DATA_DIR.mkdir(parents=True, exist_ok=True)
+    tmp = _STORE.with_suffix(".tmp")
+    tmp.write_text(json.dumps(data, ensure_ascii=False, indent=2), "utf-8")
+    os.replace(tmp, _STORE)  # 原子写
+
+
+def get_record(key: str):
+    return _load().get(key)
+
+
+def save_record(key: str, value) -> None:
+    data = _load()
+    data[key] = value
+    _save(data)