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_tools/utils/text.py

@@ -0,0 +1,37 @@
+import unicodedata
+
+
+def parse_seconds(s: str) -> int | None:
+    """解析 '30' 或 '3*60' 形式的时长秒数,非法输入返回 None"""
+    s = s.strip()
+    if not s or not all(c.isdigit() or c == "*" for c in s):
+        return None
+    try:
+        result = 1
+        for part in s.split("*"):
+            result *= int(part)
+        return result
+    except ValueError:
+        return None
+
+
+def strip_prefix(text: str, prefixes) -> str:
+    """依次移除前缀后去空白"""
+    for p in prefixes:
+        text = text.removeprefix(p)
+    return text.strip()
+
+
+def is_number(s) -> bool:
+    """判断字符串是否可视为数字"""
+    try:
+        float(s)
+        return True
+    except ValueError:
+        pass
+    try:
+        unicodedata.numeric(s)
+        return True
+    except (TypeError, ValueError):
+        pass
+    return False