System architecture

Logical system view

The diagram shows logical boundaries. It does not claim every optional hardware or display component is already shipped.

Deployment boundary

Each station receives one isolated deployment. There is no cross-station tenant column in the business model. A future central view consumes published station contracts from outside rather than adding tenancy to every record.

Ownership boundary

One module owns each durable fact and its schema. A projection may mirror a fact but never becomes an alternate writer.

Three records may describe the same service without becoming one lifecycle:

• scheduling owns what the station announced;
• allocation owns the vehicle and bay commitments;
• cycle owns what the station observed.

Hardware boundary

Business modules depend on vendor-neutral ports for cameras, readers, barriers, intercoms, gates, printers, and payment terminals.

• Referential stores durable capability placement.
• Adapter configuration stores protocols, addresses, and credentials.
• Operational modules store observations, commands, acknowledgements, and health.
• A device acknowledgement is not proof of physical passage.