feat: add ephvm host

hosts/ephvm/configuration.nix

@@ -0,0 +1,69 @@
+{
+  pkgs,
+  lib,
+  inputs,
+  config,
+  ...
+}:
+{
+  networking.hostName = "ephvm";
+
+  profiles.base.enable = true;
+
+  vm-guest = {
+    enable = true;
+    headless = true;
+  };
+
+  vm-9p-automount = {
+    enable = true;
+    user = "matej";
+  };
+
+  localisation = {
+    timeZone = "UTC";
+    defaultLocale = "en_US.UTF-8";
+  };
+
+  virtualisation.docker = {
+    enable = true;
+    logDriver = "json-file";
+  };
+
+  # TODO:(@janezicmatej) move neovim dotfiles wiring to a cleaner place
+  home-manager.users.matej = {
+    neovim.dotfiles = inputs.nvim;
+  };
+
+  # writable claude config via 9p
+  fileSystems."/home/matej/.claude" = {
+    device = "claude";
+    fsType = "9p";
+    options = [
+      "trans=virtio"
+      "version=9p2000.L"
+      "nofail"
+      "x-systemd.automount"
+    ];
+  };
+
+  # .claude.json passed via qemu fw_cfg
+  boot.kernelModules = [ "qemu_fw_cfg" ];
+  systemd.services.claude-json = {
+    after = [ "systemd-modules-load.service" ];
+    wants = [ "systemd-modules-load.service" ];
+    wantedBy = [ "multi-user.target" ];
+    serviceConfig = {
+      Type = "oneshot";
+      RemainAfterExit = true;
+      ExecStart = pkgs.writeShellScript "claude-json" ''
+        src="/sys/firmware/qemu_fw_cfg/by_name/opt/claude.json/raw"
+        [ -f "$src" ] || exit 0
+        cp "$src" /home/matej/.claude.json
+        chown matej:users /home/matej/.claude.json
+      '';
+    };
+  };
+
+  system.stateVersion = "25.11";
+}