Document asynchronous execution properties in the BPMN modeler

[Flaurite]

Description

See issues:

• Support for additional properties for the asynchronous element execution in Modeler jmix#5469
• Support asynchronous execution flags for elements that lack them in the BPMN Modeler jmix#5625

Asynchronous execution flags per modeler element

Attributes (BPMN XML): flowable:async, flowable:exclusive, flowable:asyncLeave, flowable:asyncLeaveExclusive.
✅ = exposed in the element's properties panel · — = not applicable (not shown).

Element	async	exclusive	asyncLeave	asyncLeaveExclusive
Service Task	✅	✅	✅	✅
Script Task	✅	✅	✅	✅
Business Rule Task	✅	✅	✅	✅
Send Email Task	✅	✅	✅	✅
Send Notification Task	✅	✅	✅	✅
Entity Data Task	✅	✅	✅	✅
Call Activity	✅	✅	✅	✅
Sub-Process	✅	✅	✅	✅
User Task	✅	✅	✅	✅
Parallel Gateway	✅	✅	✅	✅
Inclusive Gateway	✅	✅	✅	✅
Exclusive Gateway	✅	✅	✅	✅
Event-based Gateway	✅	✅	✅	✅
Start event	✅	✅	✅	✅
Timer / Message / Signal / Error / Escalation event — with outgoing flow (start, intermediate catch/throw, boundary)	✅	✅	✅	✅
Timer / Message / Signal / Error / Escalation event — end position (bpmn:EndEvent)	✅	✅	—	—
Terminate End event	✅	✅	—	—
None End event	✅	✅	—	—

Notes for documentation:

• exclusive is only meaningful together with async; asyncLeaveExclusive only together with asyncLeave. In the panel the exclusivity checkbox is editable only while its async flag is on.
• End events have no outgoing sequence flow, so the "asynchronous leave" pair (asyncLeave, asyncLeaveExclusive) is not shown for them.
• Sequence flows, pools and lanes are not async-capable and expose none of these attributes.