feat(T01): bootstrap IHP v1.5 project scaffold

Merged ihp-new generated scaffold into repo. Sets appName to inter-hub,
adds Nix flake with IHP inputs, devenv config, and standard IHP project
structure. Nix + ihp-new + direnv installed system-wide.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Config/nix/hosts/production/hardware-configuration.nix

@@ -0,0 +1,13 @@
+# Autogenerated hardware config
+# Run 'nixos-generate-config' on the deployment host to generate it
+{ config, lib, pkgs, modulesPath, ... }:
+
+{
+    imports = [
+        # For AWS EC2: "${inputs.nixpkgs}/nixos/modules/virtualisation/amazon-image.nix"
+    ];
+
+    # For testing purposes only, remove on bootable hosts.
+    boot.loader.grub.enable = pkgs.lib.mkDefault false;
+    fileSystems."/".device = pkgs.lib.mkDefault "/dev/null";
+}