docs/PORTS.md reserved ranges summary incorrectly lists port 5564 (portos-slotstream) as unassigned

[atomantic]

Problem

In docs/PORTS.md:135, the "Recommended Port Ranges" section summarizes the 5562-5569 block:

| 5562-5569 | Reserved for PortOS extensions. Assigned: 5562 whisper, 5563 Eidoverse bridge (on demand), 5568 llama-server. Unassigned but still reserved: 5564-5567, 5569 |

This claims port 5564 is unassigned. However, port 5564 is allocated to portos-slotstream across the codebase and in the same document:

• docs/PORTS.md:39 (| 5564 | portos-slotstream | - | Loopback SSD-streaming MoE runtime...)
• docs/PORTS.md:150 (The on-demand ports (5563, 5564, 5568) are the easiest to get wrong...)
• server/lib/ports.js:20 (SLOTSTREAM: 5564)
• ecosystem.config.cjs:124

When #5815 added slotstream, line 135 was overlooked.

Trigger

A contributor or operator consulting the Recommended Port Ranges table in docs/PORTS.md (line 135) to allocate an unused port for a new extension.

Impact

Allocating port 5564 for a new service causes a collision with portos-slotstream. As detailed in docs/PORTS.md:138-158, port collisions on on-demand loopback services can be silent rather than throwing EADDRINUSE, causing one process to quietly fail to receive connections.

Fix

1. Update docs/PORTS.md line 135:
   • Add 5564 slotstream (on demand) to the Assigned: list.
   • Update the unassigned range from 5564-5567, 5569 to 5565-5567, 5569.
2. Ensure consistency with server/lib/ports.js and server/lib/ports.test.js.

Alternative rejected: Reallocating slotstream to another port — rejected because 5564 is already established in ecosystem.config.cjs, server/lib/ports.js, and slotstreamServerManager.js.

Acceptance Criteria

• docs/PORTS.md line 135 marks port 5564 as assigned to slotstream.
• docs/PORTS.md line 135 lists 5565-5567, 5569 as unassigned.
• npm test -- server/lib/ports.test.js passes.