Camp: auto-break when party moves to a different room

Camp was a stationary "rest here until the next briefing" intent, but
nothing struck it when the autopilot / !zone advance / fork picks walked
the party into a new room. The stale CampState then blocked !camp <type>
with "already camped" even though the player was several rooms away.

autoBreakCampOnMove clears the camp (no rest bonuses — those only land
at briefing time via processOvernightCamp) whenever Camp.RoomIndex no
longer matches run.CurrentRoom. Wired into advanceOnceWithOpts (covers
advance/autopilot, complete/fork/next-room branches all surface a
"⛺ Camp struck" banner) and zoneCmdGo (fork commit).

internal/plugin/dnd_zone_cmd_graph.go

@@ -196,6 +196,9 @@ func (p *AdventurePlugin) zoneCmdGo(ctx MessageContext, rest string) error {
 	nextRoom := nodeKindToRoomType(nextNode.Kind)
 	nextIdx := run.CurrentRoom + 1
 	var b strings.Builder
+	if kind := autoBreakCampOnMove(ctx.Sender); kind != "" {
+		b.WriteString(fmt.Sprintf("⛺ Camp struck (**%s**) — the party moved on.\n\n", kind))
+	}
 	b.WriteString(fmt.Sprintf("➡ You take the path: **%s**.\n\n", chosen.Label))
 	if nextRoom == RoomBoss {
 		if line := composeBossEntry(zone.ID, run.RunID, nextIdx); line != "" {