Where does Heidi run, and where does my data live?
Heidi is a hosted product. Your company's instance is its own tenant with strict isolation: every operation carries tenant identity, and one company's Heidi cannot read anything belonging to another.
Isolation is enforced structurally, not by convention. Storage, queues, memory, caches, credentials, and receipts are all tenant-scoped, and an operation without tenant context fails closed instead of defaulting to anything.
The full isolation story, including deletion semantics, is at falkster.ai/answers/tenant-isolation.