feat: modmail ticket system with Components V2 + HTML transcripts

- DM-based modmail: user DMs bot -> ticket channel created
- Staff relay: messages in ticket -> DM to user
- Configurable categories via /modmail addcategory
- Setup via /modmail setup (category, staff role, log channel)
- Close command: /close or !close -> HTML transcript generated
- Components V2: Container, TextDisplay, Separator, persistent views
- Transcript: dark theme HTML with staff badges, avatars, timestamps

utils/modmail_config.py

@@ -0,0 +1,110 @@
+import json
+from pathlib import Path
+
+from config import DATA_DIR
+
+CONFIG_PATH = DATA_DIR / "modmail.json"
+
+DEFAULT_CONFIG = {
+    "enabled": False,
+    "category_id": None,
+    "staff_role_id": None,
+    "log_channel_id": None,
+    "categories": {},
+    "open_tickets": {},
+}
+
+
+def _load() -> dict:
+    if CONFIG_PATH.exists():
+        with open(CONFIG_PATH, "r", encoding="utf-8") as f:
+            return json.load(f)
+    return DEFAULT_CONFIG.copy()
+
+
+def _save(data: dict):
+    CONFIG_PATH.parent.mkdir(parents=True, exist_ok=True)
+    with open(CONFIG_PATH, "w", encoding="utf-8") as f:
+        json.dump(data, f, indent=2, ensure_ascii=False)
+
+
+def get_config() -> dict:
+    return _load()
+
+
+def set_enabled(guild_id: int, enabled: bool):
+    data = _load()
+    data["enabled"] = enabled
+    _save(data)
+
+
+def set_category(guild_id: int, category_id: int):
+    data = _load()
+    data["category_id"] = category_id
+    _save(data)
+
+
+def set_staff_role(guild_id: int, role_id: int):
+    data = _load()
+    data["staff_role_id"] = role_id
+    _save(data)
+
+
+def set_log_channel(guild_id: int, channel_id: int):
+    data = _load()
+    data["log_channel_id"] = channel_id
+    _save(data)
+
+
+def add_category(guild_id: int, name: str, emoji: str, description: str = ""):
+    data = _load()
+    data["categories"][name.lower()] = {
+        "name": name,
+        "emoji": emoji,
+        "description": description,
+    }
+    _save(data)
+
+
+def remove_category(guild_id: int, name: str):
+    data = _load()
+    data["categories"].pop(name.lower(), None)
+    _save(data)
+
+
+def get_categories() -> dict:
+    data = _load()
+    return data.get("categories", {})
+
+
+def register_ticket(guild_id: int, user_id: int, channel_id: int, category: str):
+    data = _load()
+    data["open_tickets"][str(user_id)] = {
+        "channel_id": channel_id,
+        "category": category,
+        "guild_id": guild_id,
+    }
+    _save(data)
+
+
+def unregister_ticket(user_id: int):
+    data = _load()
+    data["open_tickets"].pop(str(user_id), None)
+    _save(data)
+
+
+def get_ticket_by_user(user_id: int) -> dict | None:
+    data = _load()
+    return data["open_tickets"].get(str(user_id))
+
+
+def get_ticket_by_channel(channel_id: int) -> dict | None:
+    data = _load()
+    for uid, ticket in data.get("open_tickets", {}).items():
+        if ticket["channel_id"] == channel_id:
+            return {"user_id": int(uid), **ticket}
+    return None
+
+
+def is_enabled() -> bool:
+    return _load().get("enabled", False)