feat(ci): add GitLab CE + Jenkins LTS one-click generators

Add 'ci' category with two service generators (gitlab, jenkins),
following project conventions (quoted heredocs, PKG_INSTALL, bash_header,
warnings + post_steps). Jenkins WAR URLs pinned in a class dict to
avoid 404s. app.py + generators/__init__.py updated to register.

app.py

@@ -23,6 +23,7 @@ from generators.system import *      # noqa: F401
 from generators.network import *     # noqa: F401
 from generators.databases import *   # noqa: F401
 from generators.monitoring import *  # noqa: F401
+from generators.ci import *          # noqa: F401
 
 BASE_DIR = Path(__file__).parent
 app = Flask(__name__, instance_path=str(BASE_DIR / "instance"))