Fix port allocation scoped per-site for transport services

[Copilot]

Port allocation for TCP/UDP transport services was global — port numbers from site 1 were treated as unavailable when allocating for site 2, causing unexpectedly high ports in new sites.

Changes

migrations/20260506000000-transport-service-site-scoped-port-constraint.js (new)

• Adds siteId column to TransportServices, backfilled via Service → Container
• Drops the global (protocol, externalPort) unique index
• Adds a site-scoped (siteId, protocol, externalPort) unique index

models/transport-service.js

• Denormalized siteId field added to the model with a belongsTo Site association
• nextAvailablePortInRange now requires siteId and filters directly on the TransportServices table — no joins needed

// Before: scans all sites
static async nextAvailablePortInRange(protocol, minPort, maxPort, transaction = null)

// After: scoped to site via denormalized siteId column
static async nextAvailablePortInRange(protocol, minPort, maxPort, siteId, transaction = null)

routers/containers.js

• Both POST and PUT container handlers pass siteId to nextAvailablePortInRange and include it in TransportService.create()
• Corrected pre-existing typo: max port 65565 → 65535 (valid TCP/UDP ceiling)

[runleveldev]

@copilot there is a unique constraint on (protocol, externalPort) in the TransportServices model. To support this change, the unique constraint should instead be on (siteId, protocol, externalPort). There is a one-to-one relationship from TransportService to Sites via TransportService(serviceId)->Service(containerId)->Container(nodeId)->Node(siteId). Denormalization of the TransportService model may be nessecary to apply this change.

[Copilot]

@copilot there is a unique constraint on (protocol, externalPort) in the TransportServices model. To support this change, the unique constraint should instead be on (siteId, protocol, externalPort). T...

Done in 5cb4f1c. siteId is now denormalized onto TransportService:

• Migration (20260506000000): adds siteId column, backfills it via Service → Container, makes it NOT NULL, drops the global (protocol, externalPort) unique index, and adds a site-scoped (siteId, protocol, externalPort) unique index
• Model: siteId field added with belongsTo Site association; nextAvailablePortInRange now filters directly by siteId on TransportServices (no joins)
• containers.js: both TransportService.create() calls now include siteId