Modularize bot: per-guild config system for roles/channels/categories

- Add utils/guild_config.py: centralized config loader per guild (data/guilds/{id}.json)
- Add commandes/config.py: /config set_role, /config set_channel, /config set_category, /config voir, /config reset
- Replace ALL hardcoded role IDs (banquier, gouvernement, citoyen, staff, ems, permis, fbm, ursaff, etc.) with guild_config lookups
- Replace ALL hardcoded channel IDs (welcome, candidature, questions, mp_reception) with guild_config lookups
- Replace ALL hardcoded category IDs (ticket) with guild_config lookups
- Remove duplicate commandes/welcome_message.py (kept utils/ version)
- Remove 20+ hardcoded snowflake IDs across 22 files
- Guilds configure via /config on Discord, no code changes needed

commandes/ajouter_argent.py

@@ -3,8 +3,7 @@ from discord import app_commands
 from discord.ext import commands
 import json
 from datetime import datetime
-
-BANQUIER_ROLE_ID = 1360314740567576616  # ID du rôle des banquiers  # ID du rôle banquier  # ID du rôle banquier
+from utils.guild_config import has_role
 
 class AjouterArgent(commands.Cog):
     def __init__(self, bot):
@@ -34,7 +33,7 @@ class AjouterArgent(commands.Cog):
         banque: app_commands.Choice[str] = None
     ):
         # Vérification du rôle
-        if not any(role.id == BANQUIER_ROLE_ID for role in interaction.user.roles):
+        if not has_role(interaction.user, "banquier"):
             await interaction.response.send_message(
                 "❌ Vous n'avez pas la permission d'utiliser cette commande.",
                 ephemeral=True