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.

app/sovran_systemsos_web/server.py

@@ -1112,7 +1112,7 @@ def _get_firewall_allowed_ports() -> dict[str, set[int]]:
         )
         if proc.returncode == 0:
             for line in proc.stdout.splitlines():
-                # e.g. ACCEPT tcp  -- ... dpt:443  or  dpts:7882:7894
+                # e.g. ACCEPT tcp  -- ... dpt:443  or  dpts:40000:40099
                 m = re.search(r'(tcp|udp).*dpts?:(\d+)(?::(\d+))?', line)
                 if m:
                     proto_match = m.group(1)
@@ -1170,7 +1170,7 @@ def _resolve_all_addresses_cached(domain: str) -> list[str]:
 
 
 def _port_range_to_ints(port_str: str) -> list[int]:
-    """Convert a port string like ``"443"``, ``"30000-40000"`` to a list of ints."""
+    """Convert a port string like ``"443"``, ``"40000-40099"`` to a list of ints."""
     port_str = port_str.strip()
     if re.match(r'^\d+$', port_str):
         return [int(port_str)]