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/home/idle.nix

@@ -0,0 +1,13 @@
+{ config, pkgs, ... }:
+
+let
+  stateFile = "${config.home.homeDirectory}/.config/home-manager/idle-state.json";
+  idleState = if builtins.pathExists stateFile then 
+    builtins.fromJSON (builtins.readFile stateFile)
+  else { enabled = true; };
+in
+{
+  services.hypridle = {
+    enable = idleState.enabled;
+  };
+}