Adv 2.0 D&D Phase 12 E6a: Multi-region expedition map (!map)

Adds renderRegionChain — for tier 4-5 multi-region zones, renders the
4-region progression (e.g. ST──DO──IW──TDT for Underdark) with ✓
cleared / ▶ here / · pending markers, and ⛺ overlay where a base
camp has been pitched. Single-region zones skip the chain and fall
through to the existing renderZoneMap room layout.

!map (top-level) and !expedition map both invoke handleExpeditionMapCmd
which composes: region chain → current region label → per-run room
map → legend. Region abbreviations are decoded in a "Regions:" footer
so the glyph row stays compact.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

internal/plugin/dnd_expedition_cmd.go

@@ -68,6 +68,8 @@ func (p *AdventurePlugin) handleDnDExpeditionCmd(ctx MessageContext, args string
 		return p.handleExtractCmd(ctx, "")
 	case "resume":
 		return p.handleResumeCmd(ctx, rest)
+	case "map", "m":
+		return p.handleExpeditionMapCmd(ctx, "")
 	default:
 		return p.SendDM(ctx.Sender, expeditionHelpText())
 	}
@@ -85,7 +87,8 @@ func expeditionHelpText() string {
 	b.WriteString("`!expedition log` — last 5 log entries\n")
 	b.WriteString("`!expedition abandon` — end the expedition (no rewards)\n")
 	b.WriteString("`!extract` — voluntary extraction (1 day, resumable for 7 days)\n")
-	b.WriteString("`!resume [Ns] [Md]` — resume an extracted expedition")
+	b.WriteString("`!resume [Ns] [Md]` — resume an extracted expedition\n")
+	b.WriteString("`!map` — region/room ASCII map")
 	return b.String()
 }