Refactor: Simplify module structure and reorganize services

- Removed system/ directory, merged applications into users/geir.nix
- Simplified fonts.nix to bare minimum (users can add more)
- Moved transmission.nix to sleeper-service/services/ (machine-specific)
- Organized grey-area services into services/ directory
- Updated import paths and tested all configurations
- Added research documentation for deploy-rs and GNU Stow

machines/grey-area/nixos/forgejo.nix

@@ -1,26 +0,0 @@
-{ pkgs, config, ... }:
-{
-  services.forgejo = {
-    enable = true;
-    #user = "git";
-  };
-   
-  services.forgejo.settings = {
-    DEFAULT = {
-      RUN_MODE = "prod";
-    };
-    service = {
-      DISABLE_REGISTRATION = true;
-    };
-    server = {
-      ROOT_URL = "http://apps:3000";
-      SSH_DOMAIN = "git.geokkjer.eu";
-    };
-    repository = {
-      ENABLE_PUSH_CREATE_USER = true;
-    };
-    other = {
-      SHOW_FOOTER_VERSION = true;
-    };
-  };
-}