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/vscode.nix

@@ -0,0 +1,14 @@
+{ config, pkgs, ... }:
+
+{
+  programs.vscode = {
+    enable = true;
+    package = pkgs.vscode;
+    userSettings = {
+      "update.mode" = "none";
+      "workbench.colorTheme" = "Nomarchy Theme"; # Example, would need to be generated
+      "window.titleBarStyle" = "custom";
+    };
+    # extensions = with pkgs.vscode-extensions; [ ... ];
+  };
+}