docs/hub: update Element Calling port guidance to the new port set

User-facing polish to match the element-calling port changes:

- helpers.js: port-forward guide example now shows the 40000-40099 range
  instead of the removed 30000-40000.
- versions.json: livekit dev fallback 1.5.2 -> 1.13.6 (the Nix-generated
  version in sovran-hub.nix already derives from pkgs.livekit.version).
- server.py: docstring/comment examples reference 40000-40099.
- CHANGELOG.md: record the calling changes under [Unreleased].

The tile/modal port tables themselves are data-driven from server.py's
port_requirements / _PORTS_ELEMENT_CALLING (updated in the previous commit),
so no further UI changes are needed.

CHANGELOG.md

@@ -7,6 +7,21 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ---
 
+## [Unreleased]
+
+### Changed
+- Element Calling: pin LiveKit to 1.13.6 and advertise the LAN interface
+  (rtc.advertise_internal_ip) so Wi-Fi callers get a local ICE candidate and
+  calls no longer depend on router NAT hairpin
+- Element Calling: use a single UDP media mux (7882); move the TURN relay to
+  40000-40099 and remove the unreachable 5349 TURN/TLS listener
+- Hub: update Element Calling router-port guidance to the new port set
+
+### Fixed
+- Element Calling: TURN relay could not deliver media to the SFU on routers
+  without NAT loopback (turn.allow_restricted_peer_cidrs now permits the LAN
+  subnet derived from the primary interface)
+
 ## [1.1.3] - 2026-08-27
 
 ### Added