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

bin/nomarchy-install-docker-dbs

@@ -1,12 +1,30 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
-# Install one of the supported databases in a Docker container with the suitable development options.
+# Configure Docker declaratively and provide instructions for running DBs.
 # Usually called via Install > Development > Docker DB from the Nomarchy Menu.
 
+FEATURE_FILE="/etc/nixos/nomarchy-features/docker.nix"
+
+if [ ! -f "$FEATURE_FILE" ]; then
+    sudo mkdir -p "/etc/nixos/nomarchy-features"
+    cat <<EOF | sudo tee "$FEATURE_FILE" > /dev/null
+{ config, pkgs, ... }:
+{
+  virtualisation.docker.enable = true;
+  users.users.\${config.users.users.mainUser}.extraGroups = [ "docker" ]; # Replace mainUser with your username
+}
+EOF
+    echo "Created $FEATURE_FILE to enable Docker."
+    echo "IMPORTANT: To finish enabling Docker, add './nomarchy-features/docker.nix' to your imports list in /etc/nixos/system.nix or /etc/nixos/flake.nix,"
+    echo "then run 'sys-update'."
+    echo "Wait for the update to complete before running docker commands."
+    echo ""
+fi
+
 options=("MySQL" "PostgreSQL" "Redis" "MongoDB" "MariaDB" "MSSQL")
 
 if (( $# == 0 )); then
-  choices=$(printf "%s\n" "${options[@]}" | gum choose --header "Select database (return to install, esc to cancel)") || main_menu
+  choices=$(printf "%s\n" "${options[@]}" | gum choose --header "Select database (ensure Docker is running)") || exit 0
 else
   choices="$@"
 fi