Implement BPMN 2.0 as the first executable business notation. Scope: events, tasks, XOR/AND/OR gateways, sequence/message flows, pools and lanes; contextual palette; Rust/WASM validation; BPMN XML import/export. Acceptance: invalid flows are explained on-canvas and BPMN XML round-trips with reference examples.
Implement BPMN 2.0 as the first executable business notation. Scope: events, tasks, XOR/AND/OR gateways, sequence/message flows, pools and lanes; contextual palette; Rust/WASM validation; BPMN XML import/export. Acceptance: invalid flows are explained on-canvas and BPMN XML round-trips with reference examples.