feat(nix): add Nextcloud Claude Bot integration

- Added configuration for Nextcloud Claude Bot, including NixOS module, secrets management, and example setup files.
- Introduced a Python-based HTTP server for handling webhook events and interacting with Nextcloud Talk.
- Integrated necessary dependencies and systemd service for seamless operation.

systems/x86_64-linux/mx/nextcloud-claude-bot/default.nix

@@ -0,0 +1,31 @@
+{ config, ... }:
+{
+  imports = [ ./module.nix ];
+
+  services.nextcloud-claude-bot = {
+    enable = true;
+    nextcloudUrl = "https://nc.hoyer.xyz";
+    botSecretFile = config.sops.secrets."nextcloud-claude-bot/secret".path;
+    allowedUsers = [ "harald" ];
+  };
+
+  sops.secrets."nextcloud-claude-bot/secret" = {
+    sopsFile = ../../../../.secrets/hetzner/nextcloud-claude-bot.yaml;
+    restartUnits = [ "nextcloud-claude-bot.service" ];
+  };
+
+  # Nginx location for Nextcloud to send webhooks to the bot
+  services.nginx.virtualHosts."nc.hoyer.xyz".locations."/_claude-bot/" = {
+    proxyPass = "http://127.0.0.1:8085/";
+    extraConfig = ''
+      proxy_set_header Host $host;
+      proxy_set_header X-Real-IP $remote_addr;
+      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+      proxy_set_header X-Forwarded-Proto $scheme;
+
+      # Only allow from localhost (Nextcloud on same server)
+      allow 127.0.0.1;
+      deny all;
+    '';
+  };
+}