docs: refresh nodes + pairing docs

docs/concepts/architecture.md

@@ -5,7 +5,7 @@ read_when:
 ---
 # Gateway architecture
 
-Last updated: 2026-01-19
+Last updated: 2026-01-22
 
 ## Overview
 
@@ -34,7 +34,8 @@ Last updated: 2026-01-19
 
 ### Nodes (macOS / iOS / Android / headless)
 - Connect to the **same WS server** with `role: node`.
-- Pair with the Gateway to receive a token.
+- Provide a device identity in `connect`; pairing is **device‑based** (role `node`) and
+  approval lives in the device pairing store.
 - Expose commands like `canvas.*`, `camera.*`, `screen.record`, `location.get`.
 
 Protocol details:

docs/concepts/presence.md

@@ -52,10 +52,10 @@ Instances list, `client.mode === "cli"` is **not** turned into a presence entry.
 Clients can send richer periodic beacons via the `system-event` method. The mac
 app uses this to report host name, IP, and `lastInputSeconds`.
 
-### 4) Node bridge beacons
+### 4) Node connects (role: node)
 
-When a node bridge connection authenticates, the Gateway emits a presence entry
-for that node and refreshes it periodically so it doesn’t expire.
+When a node connects over the Gateway WebSocket with `role: node`, the Gateway
+upserts a presence entry for that node (same flow as other WS clients).
 
 ## Merge + dedupe rules (why `instanceId` matters)