refactor: centralize host and user metadata

modules/features/standard-boot.nix

@@ -1,7 +1,7 @@
 { ... }:
 {
-  flake.modules.nixos.standardBoot =
-    { pkgs, ... }:
+  flake.modules.nixos."standard-boot" =
+    { config, pkgs, ... }:
     {
       boot = {
         loader = {
@@ -10,6 +10,21 @@
             enable = true;
             consoleMode = "auto";
             configurationLimit = 5;
+            extraInstallCommands = ''
+              ENTRIES="${config.boot.loader.efi.efiSysMountPoint}/loader/entries"
+              PROFILES="/nix/var/nix/profiles"
+
+              for file in "$ENTRIES"/nixos-generation-*.conf; do
+                generation=$(${pkgs.coreutils}/bin/basename "$file" | ${pkgs.gnugrep}/bin/grep -o -E '[0-9]+')
+                timestamp=$(${pkgs.coreutils}/bin/stat -c %y "$PROFILES/system-$generation-link" 2>/dev/null | ${pkgs.coreutils}/bin/cut -d. -f1)
+
+                if [ -z "$timestamp" ]; then
+                  timestamp="Unknown Date"
+                fi
+
+                ${pkgs.gnused}/bin/sed -i "s/^version .*/version Generation $generation - $timestamp/" "$file"
+              done
+            '';
           };
         };