feat(y2q): add caddy

- Add a runit service for Caddy with a Caddyfile
- Update cloudflared runit service:
  - Add support for multiple subdomains using dynamic YAML generation
  - Each subdomain routes to Caddy running on localhost (port 8080)

home/modules/runit/services/caddy.nix

@@ -0,0 +1,32 @@
+{ pkgs, config, ... }:
+
+{
+  home.file.".config/caddy/Caddyfile".text = ''
+    {
+      http_port 8080
+      https_port 8443
+      auto_https off
+    }
+
+    # Cloudflare Tunnel
+    http://gist.toast.name {
+      # Opengist
+      reverse_proxy http://localhost:${config.runit.services.opengist.environment.OG_HTTP_PORT}
+    }
+    
+    # Tailscale
+    http://y2q.ts.toast.name {
+      # Glances
+      reverse_proxy http://localhost:61208
+    }
+  '';
+
+  runit.services.caddy = {
+    script = ''
+      exec ${pkgs.caddy}/bin/caddy run \
+        --config "$HOME/.config/caddy/Caddyfile" \
+        --adapter caddyfile
+    '';
+    log.enable = true;
+  };
+}