chore: update Nix configurations for Nixcloud and common hosts

- Add Nixcloud host configurations including networking, hardware, and system settings
- Refactor existing configurations for clarity and organization
- Remove unused podman configuration from home-manager
- Update SSH agent settings and session variables in Nixbook host

hosts/Nixcloud/nixos/networking.nix

@@ -0,0 +1,35 @@
+{ lib, ... }: {
+  # This file was populated at runtime with the networking
+  # details gathered from the active system.
+  networking = {
+    nameservers = [ "45.143.83.10"
+ "1.1.1.1"
+ "8.8.4.4"
+ ];
+    defaultGateway = "72.61.129.254";
+    defaultGateway6 = {
+      address = "2a02:4780:66::1";
+      interface = "eth0";
+    };
+    dhcpcd.enable = false;
+    usePredictableInterfaceNames = lib.mkForce false;
+    interfaces = {
+      eth0 = {
+        ipv4.addresses = [
+          { address="72.61.129.56"; prefixLength=24; }
+        ];
+        ipv6.addresses = [
+          { address="2a02:4780:66:9ac0::1"; prefixLength=48; }
+{ address="fe80::9ce8:d4ff:feb5:50d7"; prefixLength=64; }
+        ];
+        ipv4.routes = [ { address = "72.61.129.254"; prefixLength = 32; } ];
+        ipv6.routes = [ { address = "2a02:4780:66::1"; prefixLength = 128; } ];
+      };
+      
+    };
+  };
+  services.udev.extraRules = ''
+    ATTR{address}=="9e:e8:d4:b5:50:d7", NAME="eth0"
+    
+  '';
+}