feat: implement modular foundation and core system services

- Update flake.nix with 25.11 release and core inputs
- Add dedicated modules for audio (Pipewire), bluetooth, and networking
- Update GEMINI.md with the new Modular Merging Architecture blueprint
- Configure graphical installer ISO and test VM outputs

modules/options.nix

@@ -0,0 +1,68 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+{
+  options.nomarchy = {
+    # System-level options
+    system = {
+      enable = mkEnableOption "Nomarchy core system features";
+      
+      # Allow users to add extra system packages
+      extraPackages = mkOption {
+        type = types.listOf types.package;
+        default = [];
+        description = "Additional system-wide packages to install";
+      };
+
+      # Allow overriding system defaults
+      hostname = mkOption {
+        type = types.str;
+        default = "nomarchy";
+        description = "The system hostname";
+      };
+
+      # Allow user to inject their own NixOS modules
+      extraModules = mkOption {
+        type = types.listOf types.deferredModule;
+        default = [];
+        description = "Extra NixOS modules to include";
+      };
+    };
+
+    # Home-level options
+    home = {
+      enable = mkEnableOption "Nomarchy home environment features";
+      
+      # Allow users to add extra user packages
+      extraPackages = mkOption {
+        type = types.listOf types.package;
+        default = [];
+        description = "Additional user-level packages to install";
+      };
+
+      # Configuration for the environment
+      terminal = mkOption {
+        type = types.enum [ "alacritty" "kitty" "ghostty" ];
+        default = "alacritty";
+        description = "Preferred terminal emulator";
+      };
+
+      # Allow user to inject their own Home Manager modules
+      extraModules = mkOption {
+        type = types.listOf types.deferredModule;
+        default = [];
+        description = "Extra Home Manager modules to include";
+      };
+
+      # Theming overrides
+      themeOverride = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = "Force a specific theme (ignoring state files)";
+      };
+    };
+
+    # Hardware flags (already exists in hardware.nix, but good to keep in mind)
+  };
+}