fix(scripting): supply ZoneCompletePct to script-rendered maps

[pruuk]

PR: fix %!d(<nil>) in script-rendered map titles

Canonical PR description for the map-bug fix (branch fix/map-zonecompletepct,
off GoMudEngine/GoMud:master). Separate from the AI-port PR.

Description

Looking at a map sign (or any map produced by the GetMap scripting
function) renders a broken title — e.g. Map of Frostfang (%!d(<nil>)%) — instead
of a percentage.

The shared maps/map template formats the title with a zone-completion percent:
printf "%s (%d%%)" .Title .ZoneCompletePct. The map command supplies
ZoneCompletePct, but GetMap (internal/scripting/room_func.go, used by map
signs and other scripted maps) did not — so the template formatted nil with
%d and leaked %!d(<nil>) into the title.

Reproducible with a raw telnet client (no special client) via look <map sign>
in Frostfang's Town Square — so it is not a client/encoding artifact.

GetMap has no viewing user to measure exploration against (unlike the map
command), so it now defaults ZoneCompletePct to 0, matching the map
command's own fallback (internal/usercommands/skill.map.go). Script-rendered
map titles now read e.g. Map of Frostfang (0%).

Changes

• internal/scripting/room_func.go — GetMap now includes ZoneCompletePct: 0
  in the template data passed to maps/map, preventing the %!d(<nil>) leak.

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Notes

0 is the minimal, safe default that matches existing behavior; maintainers may
prefer signs to show the viewing player's actual exploration percent (would
require threading a user into GetMap) or to omit the percent for static signs —
happy to adjust. Found by an AI playtest harness driving a bug-finder
personality (verified server-side with a raw socket client).

[pruuk]

Same here. I don't seem to have permissions to run the CI tests.