Adv 2.0 D&D Phase 12 E4a: Region data model + zone registry

Spec: gogobee_expedition_system.md §11. Tier 4–5 zones (Underdark,
Dragon's Lair, Abyss Portal) split into 4 regions each. ExpeditionRegion
struct + per-zone registry; CurrentRegion(e) defaults to Order==1 when
unset; RegionState helpers persist regions_cleared / regions_visited /
base_camps as []string lists. Single-region zones return nil.

Tests cover registry shape (4 per zone, last is IsZoneBoss), lookups,
default current region, and round-trip persistence through DB.

internal/plugin/dnd_expedition_region_test.go

@@ -0,0 +1,121 @@
+package plugin
+
+import (
+	"testing"
+
+	"maunium.net/go/mautrix/id"
+)
+
+func TestRegionsForZone_OnlyMultiRegion(t *testing.T) {
+	for _, z := range []ZoneID{ZoneUnderdark, ZoneDragonsLair, ZoneAbyssPortal} {
+		rs := regionsForZone(z)
+		if len(rs) != 4 {
+			t.Errorf("zone %s: got %d regions, want 4", z, len(rs))
+		}
+		if !IsMultiRegionZone(z) {
+			t.Errorf("IsMultiRegionZone(%s) = false", z)
+		}
+		// Verify last region marks IsZoneBoss; first does not.
+		if rs[0].IsZoneBoss {
+			t.Errorf("zone %s: first region marked IsZoneBoss", z)
+		}
+		if !rs[len(rs)-1].IsZoneBoss {
+			t.Errorf("zone %s: last region not marked IsZoneBoss", z)
+		}
+		// Verify Order is 1..N.
+		for i, r := range rs {
+			if r.Order != i+1 {
+				t.Errorf("zone %s: regions[%d].Order = %d", z, i, r.Order)
+			}
+			if r.ZoneID != z {
+				t.Errorf("zone %s: region %s has ZoneID %s", z, r.ID, r.ZoneID)
+			}
+		}
+	}
+	// Non-multi-region zone returns nil.
+	if rs := regionsForZone(ZoneSunkenTemple); rs != nil {
+		t.Errorf("ZoneSunkenTemple regions = %v, want nil", rs)
+	}
+	if IsMultiRegionZone(ZoneSunkenTemple) {
+		t.Error("ZoneSunkenTemple should not be multi-region")
+	}
+}
+
+func TestRegionLookups(t *testing.T) {
+	if r, ok := firstRegion(ZoneUnderdark); !ok || r.ID != "underdark_surface_tunnels" {
+		t.Errorf("firstRegion underdark = %+v / %v", r, ok)
+	}
+	if r, ok := nextRegion(ZoneUnderdark, "underdark_surface_tunnels"); !ok || r.ID != "underdark_drow_outpost" {
+		t.Errorf("nextRegion = %+v / %v", r, ok)
+	}
+	if _, ok := nextRegion(ZoneUnderdark, "underdark_deep_throne"); ok {
+		t.Error("nextRegion past last should be false")
+	}
+	if _, ok := findRegion(ZoneUnderdark, "no_such_region"); ok {
+		t.Error("findRegion of missing id returned ok")
+	}
+}
+
+func TestCurrentRegion_DefaultsToFirst(t *testing.T) {
+	setupZoneRunTestDB(t)
+	uid := id.UserID("@region-cur:example.org")
+	defer cleanupExpeditions(uid)
+
+	exp, err := startExpedition(uid, ZoneUnderdark, "", ExpeditionSupplies{Max: 10, Current: 10, DailyBurn: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+	r, ok := CurrentRegion(exp)
+	if !ok {
+		t.Fatal("CurrentRegion returned !ok")
+	}
+	if r.ID != "underdark_surface_tunnels" {
+		t.Errorf("CurrentRegion default = %s, want underdark_surface_tunnels", r.ID)
+	}
+
+	// Single-region zone returns false.
+	cleanupExpeditions(uid)
+	exp2, err := startExpedition(uid, ZoneSunkenTemple, "", ExpeditionSupplies{Max: 10, Current: 10, DailyBurn: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, ok := CurrentRegion(exp2); ok {
+		t.Error("CurrentRegion on single-region zone returned ok")
+	}
+}
+
+func TestRegionStateLists_PersistAndRoundTrip(t *testing.T) {
+	setupZoneRunTestDB(t)
+	uid := id.UserID("@region-state:example.org")
+	defer cleanupExpeditions(uid)
+
+	exp, err := startExpedition(uid, ZoneUnderdark, "", ExpeditionSupplies{Max: 10, Current: 10, DailyBurn: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if changed, err := addRegionListEntry(exp, regionStateClearedKey, "underdark_surface_tunnels"); err != nil || !changed {
+		t.Fatalf("first add: changed=%v err=%v", changed, err)
+	}
+	if changed, err := addRegionListEntry(exp, regionStateClearedKey, "underdark_surface_tunnels"); err != nil || changed {
+		t.Errorf("duplicate add: changed=%v err=%v (want false/nil)", changed, err)
+	}
+	if !IsRegionCleared(exp, "underdark_surface_tunnels") {
+		t.Error("IsRegionCleared after add = false")
+	}
+
+	// Round-trip through DB.
+	loaded, err := getActiveExpedition(uid)
+	if err != nil || loaded == nil {
+		t.Fatalf("reload: %v / %v", loaded, err)
+	}
+	if !IsRegionCleared(loaded, "underdark_surface_tunnels") {
+		t.Error("IsRegionCleared after reload = false (state did not persist)")
+	}
+	if IsRegionCleared(loaded, "underdark_drow_outpost") {
+		t.Error("IsRegionCleared for unwritten region = true")
+	}
+	if HasBaseCampAt(loaded, "underdark_drow_outpost") {
+		t.Error("HasBaseCampAt unset = true")
+	}
+}