Branching zones G8g: Dragon's Lair converging mid-fork + capstone 3-way

T5 zone, seventh authored graph. Shape: long approach (kobold_warrens
→ drake_pens) → binary mid-fork that converges at the elite
(wyrmlings_nest) → 3-way capstone fork into the boss
(direct / CHA bargain / Perception-found hoard_pillar secret).

First zone combining two distinct fork stages where the first converges
diamond-style and the second spreads triple-wide. Secret carries
LootBias 2.5 — highest of any shipping zone, reserved for T5 — locked
in by TestDragonsLairGraph_LootBiasEscalation.

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

internal/plugin/zone_graph_dragons_lair_test.go

@@ -0,0 +1,62 @@
+package plugin
+
+import "testing"
+
+func TestDragonsLairGraph_Registered(t *testing.T) {
+	g, ok := zoneGraphRegistry[ZoneDragonsLair]
+	if !ok {
+		t.Fatal("zoneDragonsLairGraph not registered")
+	}
+	if len(g.Nodes) != 12 {
+		t.Errorf("nodes = %d, want 12", len(g.Nodes))
+	}
+}
+
+// TestDragonsLairGraph_Fork1Converges verifies the binary mid-fork
+// converges at wyrmlings_nest.
+func TestDragonsLairGraph_Fork1Converges(t *testing.T) {
+	g := zoneDragonsLairGraph()
+	for _, mid := range []string{"dragons_lair.ash_bridge", "dragons_lair.treasure_vault"} {
+		outs := g.outgoingEdges(mid)
+		if len(outs) != 1 || outs[0].To != "dragons_lair.wyrmlings_nest" {
+			t.Errorf("%s outs = %+v, want single edge to wyrmlings_nest", mid, outs)
+		}
+	}
+}
+
+// TestDragonsLairGraph_Fork2Capstone verifies the late fork has 3
+// distinct paths to the boss, each through its own capstone node.
+func TestDragonsLairGraph_Fork2Capstone(t *testing.T) {
+	g := zoneDragonsLairGraph()
+	outs := g.outgoingEdges("dragons_lair.fork2")
+	if len(outs) != 3 {
+		t.Fatalf("fork2 outgoing = %d, want 3", len(outs))
+	}
+	for _, leaf := range []string{
+		"dragons_lair.direct_confrontation",
+		"dragons_lair.dragon_bargain",
+		"dragons_lair.hoard_pillar",
+	} {
+		if !reachable(g, leaf, "dragons_lair.boss") {
+			t.Errorf("%s unreachable to boss", leaf)
+		}
+	}
+	// Locks escalate: open / CHA 16 / Perception 17 (T5 secret bias).
+	for _, e := range outs {
+		if e.To == "dragons_lair.hoard_pillar" {
+			if dc := lockDataInt(e.LockData, "dc", 0); dc < 17 {
+				t.Errorf("hoard_pillar DC = %d, want >= 17 (T5)", dc)
+			}
+		}
+	}
+}
+
+// TestDragonsLairGraph_LootBiasEscalation verifies the T5 secret has
+// the highest loot bias of any authored zone (≥ 2.5).
+func TestDragonsLairGraph_LootBiasEscalation(t *testing.T) {
+	g := zoneDragonsLairGraph()
+	hoard := g.Nodes["dragons_lair.hoard_pillar"]
+	if hoard.Content.LootBias < 2.5 {
+		t.Errorf("hoard_pillar LootBias = %v, want >= 2.5 (T5 secret)", hoard.Content.LootBias)
+	}
+}