chore: replace real IPs in docs and configs with placeholders

Operator-facing IPs in user-visible configs/docs (examples, tutorials,
packaging, sidecar templates) are now the resolvable hostnames of the
public test fleet (test-us01.fips.network, etc.) so they keep working
without baking specific addresses into examples.

Doc-comment and test fixtures in src/config/transport.rs use RFC 5737
TEST-NET-2 (198.51.100.1) so they cannot accidentally point at a real
host.

Also resyncs the openwrt-ipk fips.yaml with the common reference
(merge from master) and applies the same DNS-name swap there.

docs/tutorials/resolve-peers-via-nostr.md

@@ -96,7 +96,7 @@ You should currently have:
   ```
 
   Expect `test-us01` listed with `connectivity` active and a
-  `transport_addr` of roughly `217.77.8.91:2121`.
+  `transport_addr` of roughly `test-us01.fips.network:2121`.
 
 If either of those isn't true, finish the previous two
 tutorials first; the Nostr discovery layer is built on top of
@@ -189,7 +189,7 @@ sudo fipsctl show peers
 
 `test-us01` should appear with `connectivity` active and a
 `transport_addr` reflecting the address that was resolved from
-the advert — `217.77.8.91:2121` at time of writing. That field
+the advert — `test-us01.fips.network:2121` at time of writing. That field
 is the strong signal: nothing in your config gave the daemon
 that IP, yet there it is.