Sim: cross region boundaries; word mid-zone clears as region clears

Mirror runAutopilotWalk's multi-region auto-advance in the headless sim:
on a mid-zone stopComplete (active multi-region exp with a next region),
advanceToNextRegion and keep simulating instead of scoring a premature
"cleared". A transit error there is now recorded as halted, not cleared.

Also fix misleading run-complete wording: a non-boss region clear of a
multi-region zone now reads "Cleared {region}. The way to {next} opens
ahead." instead of "Cleared {zone}. Run complete." New midZoneRegionClear
helper shares finalizeExpeditionOnZoneClear's gating; the path is shared
with manual !region travel, so both autopilot and manual play get it.

(cherry picked from commit 5d2bba70849a0a3fdeac285cc55ea9b8fadea29c)

internal/plugin/dnd_expedition_extract.go

@@ -170,6 +170,29 @@ func (p *AdventurePlugin) finalizeExpeditionOnZoneClear(userID id.UserID, runID
 	return p.AwardCompletionMilestones(exp, false)
 }
 
+// midZoneRegionClear reports whether the just-completed run (runID) is the
+// active expedition's current run AND finishes a non-boss region of a
+// multi-region zone — i.e. a region clear that leaves the expedition active
+// with a next region to cross into. Returns the cleared region, the next
+// region, and true in that case; zero-values + false for a full zone clear,
+// a standalone run, or any read error. Used to word the run-complete message
+// (region-cleared vs zone-cleared) without re-deriving region state inline.
+func midZoneRegionClear(userID id.UserID, runID string) (cur, next ExpeditionRegion, ok bool) {
+	exp, err := getActiveExpedition(userID)
+	if err != nil || exp == nil || exp.RunID != runID || !IsMultiRegionZone(exp.ZoneID) {
+		return ExpeditionRegion{}, ExpeditionRegion{}, false
+	}
+	region, found := CurrentRegion(exp)
+	if !found || region.IsZoneBoss {
+		return ExpeditionRegion{}, ExpeditionRegion{}, false
+	}
+	nxt, found := nextRegion(exp.ZoneID, region.ID)
+	if !found {
+		return ExpeditionRegion{}, ExpeditionRegion{}, false
+	}
+	return region, nxt, true
+}
+
 // getResumableExpedition returns the most recent 'extracting' row for the
 // user, regardless of age (caller checks the 7-day window).
 func getResumableExpedition(userID id.UserID) (*Expedition, error) {

internal/plugin/dnd_zone_cmd.go

@@ -593,7 +593,16 @@ func (p *AdventurePlugin) advanceOnceWithOpts(ctx MessageContext, compact bool)
 			b.WriteString(outcome)
 			b.WriteString("\n\n")
 		}
-		b.WriteString(fmt.Sprintf("🏆 **Cleared %s.** Run complete.\n\n", zone.Display))
+		// A "complete" run is only a full zone clear when it isn't a mid-zone
+		// region clear of a multi-region zone. For the latter, name the region
+		// and point at the next one — "Cleared {zone}. Run complete." reads
+		// wrong right before the auto-advance transit block (and is shared with
+		// manual `!region travel`, which advances next).
+		if region, next, midZone := midZoneRegionClear(ctx.Sender, run.RunID); midZone {
+			b.WriteString(fmt.Sprintf("🏁 **Cleared %s.** The way to %s opens ahead.\n\n", region.Name, next.Name))
+		} else {
+			b.WriteString(fmt.Sprintf("🏆 **Cleared %s.** Run complete.\n\n", zone.Display))
+		}
 		if line := twinBeeLine(zone.ID, DMZoneComplete, run.RunID, prevIdx); line != "" {
 			b.WriteString(line)
 			b.WriteString("\n\n")

internal/plugin/expedition_sim.go

@@ -363,6 +363,29 @@ func (s *SimRunner) RunExpedition(uid id.UserID, zoneID ZoneID, walkCap int) (*S
 			res.Outcome = "tpk"
 			i = walkCap // exit
 		case stopComplete:
+			// A stopComplete that reaches the sim is normally a full zone
+			// clear (the walk auto-advances mid-zone region boundaries
+			// internally). But a mid-zone region clear can still surface
+			// here — e.g. the walk's auto-advance hit a transit error and
+			// returned stopComplete. Mirror runAutopilotWalk: if the
+			// expedition is still active in a multi-region zone with a
+			// next region, cross into it and keep simulating instead of
+			// scoring a premature "cleared".
+			if fresh, ferr := getActiveExpedition(uid); ferr == nil && fresh != nil &&
+				IsMultiRegionZone(fresh.ZoneID) {
+				if cur, ok := CurrentRegion(fresh); ok {
+					if next, ok := nextRegion(fresh.ZoneID, cur.ID); ok {
+						if _, terr := s.P.advanceToNextRegion(uid, fresh, cur, next); terr != nil {
+							res.Outcome = "halted"
+							res.StopCode = "region_transit:" + terr.Error()
+							i = walkCap
+							break
+						}
+						exp = fresh
+						break // continue the outer walk loop in the next region
+					}
+				}
+			}
 			res.Outcome = "cleared"
 			i = walkCap
 		case stopBoss, stopElite: