Create PlantUML diagrams for UML and architecture documentation including sequence, class, component, deployment, state, activity, use case, and timing diagrams plus non-UML types like C4 models, ER diagrams, Gantt charts, mindmaps, network diagrams, and wireframes. Use when the user mentions PlantUML, needs UML diagrams, wants enterprise architecture diagrams, or requires precise UML notation or C4 model support.