[nix,flake] Moves some container files around. Also updates the flake lock. [synapse] Gets the federation working

system/hosts/mcp/containers/traefik/traefik.yaml

@@ -13,6 +13,13 @@ entryPoints:
         certResolver: letsencrypt
   metrics:
     address: ":8082"
+    asDefault: false
+  matrix-federation:
+    address: ":8448"
+    asDefault: false
+    http:
+      tls:
+        certResolver: letsencrypt
 
 api:
   insecure: true