feat: implement hybrid declarative state with automatic Nix sync

installer/install.sh

@@ -1714,6 +1714,12 @@ EOF
     cat > /mnt/etc/nixos/home.nix << EOF
 { pkgs, ... }:
 {
+  imports = [
+    # Machine-managed state (theme, font, toggles).
+    # UI scripts update this file automatically.
+    ./nomarchy-state.nix
+  ];
+
   # Physical form factor — mirrors nomarchy.system.formFactor in system.nix.
   # Gates UI affordances like the waybar battery widget.
   nomarchy.formFactor = "$FORM_FACTOR";
@@ -1854,6 +1860,45 @@ EOF
             state = schema.system // { timezone = \"$_state_tz\"; };
           in builtins.toJSON state
         " | nrun jq '.' > /mnt/etc/nixos/state.json
+
+    # nomarchy-state.nix — the declarative counterpart to state.json.
+    # Imported by home.nix so UI changes are solidified in code.
+    # Generated from lib/state-schema.nix's home block.
+    nix --extra-experimental-features 'nix-command flakes' eval \
+        --impure --raw \
+        --expr "
+          let
+            flake = builtins.getFlake \"$NOMARCHY_REPO\";
+            lib = flake.inputs.nixpkgs.lib;
+            schema = import \"$NOMARCHY_REPO/lib/state-schema.nix\" { inherit lib; };
+            s = schema.home;
+          in ''
+            # DO NOT EDIT MANUALLY - Managed by Nomarchy scripts.
+            # This file mirrors your UI choices (theme, font, etc.) into the declarative
+            # Nix configuration. It is imported by your home.nix.
+            {
+              nomarchy = {
+                theme = \"\${s.theme}\";
+                fonts.monospace = \"\${s.font}\";
+                panelPosition = \"\${s.panelPosition}\";
+                wallpaper = \"\${s.wallpaper}\";
+                hyprland = {
+                  scale = \"\${s.hyprland.scale}\";
+                  gaps_in = \${toString s.hyprland.gaps_in};
+                  gaps_out = \${toString s.hyprland.gaps_out};
+                  border_size = \${toString s.hyprland.border_size};
+                };
+                toggles = {
+                  suspend = \${lib.boolToString s.suspend};
+                  screensaver = \${lib.boolToString s.screensaver};
+                  idle = \${lib.boolToString s.idle};
+                  nightlight = \${lib.boolToString s.nightlight};
+                  waybar = \${lib.boolToString s.waybar};
+                };
+              };
+            }
+          ''
+        " > /mnt/etc/nixos/nomarchy-state.nix
 }
 
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