docs: Unraid exit node approved

Approved in the Tailscale admin console, so xtrm-unraid now shows as
"offers exit node" and appears in tailscale exit-node list. The tailnet has
two exit nodes: mikrotik-tailscale (primary) and xtrm-unraid (fallback).

Neither has been exercised from the Mac. Noted that without
--exit-node-allow-lan-access an exit node cuts the client's own LAN access,
which would break an SSH session routed over Tailscale.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/CHANGELOG.md

@@ -10,7 +10,7 @@
 - **[NETWORK]** Dropped the node's old `192.168.31.0/24` advertisement. That subnet is only the macvlan shim — `br0-shim` holds `192.168.31.250/32` with a single host route to `192.168.31.4`, and no container or service lives there. No LAN subnet routes are advertised from Unraid: the MikroTik container stays primary for `192.168.10.0/24`, `.20`, `.25`, `.30`.
 - **[NETWORK]** `--accept-routes=false` and `--accept-dns=false` kept deliberately. Unraid sits *on* `192.168.10.0/24`, so accepting the hAP's route for its own subnet would loop; the resulting "peers are advertising routes but --accept-routes is false" health warning is expected, not a fault.
 - **[SERVICE]** Tailscale SSH enabled on the node. Necessary because `/etc/ssh/sshd_config` binds only `192.168.10.20` and `192.168.31.250` with no wildcard, so sshd never listens on the Tailscale IP. Port forwarding over Tailscale SSH verified (`-L 18089:127.0.0.1:80` returned HTTP 302 from the Unraid web UI).
-- **[SERVICE]** Exit node advertised from Unraid as a fallback to the hAP. **Pending manual approval** in the Tailscale admin console.
+- **[SERVICE]** Exit node advertised from Unraid as a fallback to the hAP, and approved in the Tailscale admin console the same day. The tailnet now has two exit nodes: `mikrotik-tailscale` (100.74.219.35, primary) and `xtrm-unraid` (100.100.208.69, fallback). Neither has been exercised in anger from the Mac — without `--exit-node-allow-lan-access` an exit node cuts the client's own LAN access.
 - Detail, including the root-only `AllowTcpForwarding` behaviour in Unraid's stock sshd config, in `docs/09-TAILSCALE-VPN.md`.
 
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