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.go

@@ -0,0 +1,85 @@
+package plugin
+
+// Phase G8g — Dragon's Lair (Infernus Peak) branching graph.
+//
+// T5 zone. Shape: long approach + mid-zone fork (converging at the
+// elite) + capstone 3-way fork at the boss antechamber. Combines two
+// distinct fork styles in one zone: a binary-converging fork and a
+// triple-spread capstone — escalating the player's decision-weight as
+// they descend.
+//
+//   entry → kobold_warrens → drake_pens → fork1 (binary, converges)
+//                                            ├─[unlocked]── ash_bridge ────┐
+//                                            └─[Perception DC 15]── treasure_vault ─┤
+//                                                                                   ↓
+//                                                                       wyrmlings_nest (elite young red dragon)
+//                                                                                   ↓
+//                                                                                fork2 (capstone, 3-way)
+//                                                                                   ├─[unlocked]── direct_confrontation → boss
+//                                                                                   ├─[CHA DC 16]── dragon_bargain → boss
+//                                                                                   └─[Perception DC 17]── hoard_pillar (secret) → boss
+//
+// First authored zone with two distinct fork stages where the first
+// converges (diamond-style) and the second spreads (3-way capstone).
+// Earlier zones used either-or: stacked equal-width hubs (Manor) or
+// late-only fork (Underforge). The escalation pattern ("commit, then
+// commit harder") is unique to T5.
+
+func zoneDragonsLairGraph() ZoneGraph {
+	nodes := []ZoneNode{
+		{NodeID: "dragons_lair.entry", Kind: NodeKindEntry, IsEntry: true,
+			Label: "Mountain Pass", PosX: 0, PosY: 1},
+		{NodeID: "dragons_lair.kobold_warrens", Kind: NodeKindExploration,
+			Label: "Kobold Warrens", PosX: 1, PosY: 1},
+		{NodeID: "dragons_lair.drake_pens", Kind: NodeKindExploration,
+			Label: "Drake Pens", PosX: 2, PosY: 1},
+		{NodeID: "dragons_lair.fork1", Kind: NodeKindFork,
+			Label: "The Cinder Crossing", PosX: 3, PosY: 1},
+		{NodeID: "dragons_lair.ash_bridge", Kind: NodeKindTrap,
+			Label: "Ash Bridge", PosX: 4, PosY: 0},
+		{NodeID: "dragons_lair.treasure_vault", Kind: NodeKindExploration,
+			Label: "Treasure Vault", PosX: 4, PosY: 2},
+		{NodeID: "dragons_lair.wyrmlings_nest", Kind: NodeKindElite,
+			Label: "Wyrmling's Nest", PosX: 5, PosY: 1},
+		{NodeID: "dragons_lair.fork2", Kind: NodeKindFork,
+			Label: "Hoard Approach", PosX: 6, PosY: 1},
+		{NodeID: "dragons_lair.direct_confrontation", Kind: NodeKindExploration,
+			Label: "Direct Approach", PosX: 7, PosY: 0},
+		{NodeID: "dragons_lair.dragon_bargain", Kind: NodeKindExploration,
+			Label: "Words With Infernax", PosX: 7, PosY: 1},
+		{NodeID: "dragons_lair.hoard_pillar", Kind: NodeKindSecret,
+			Label: "Hidden Hoard Pillar", PosX: 7, PosY: 2,
+			Content: ZoneNodeContent{LootBias: 2.5}},
+		{NodeID: "dragons_lair.boss", Kind: NodeKindBoss, IsBoss: true,
+			Label: "Infernax's Crown", PosX: 8, PosY: 1},
+	}
+	edges := []ZoneEdge{
+		{From: "dragons_lair.entry", To: "dragons_lair.kobold_warrens", Lock: LockNone},
+		{From: "dragons_lair.kobold_warrens", To: "dragons_lair.drake_pens", Lock: LockNone},
+		{From: "dragons_lair.drake_pens", To: "dragons_lair.fork1", Lock: LockNone},
+		// Fork1 — converges at wyrmlings_nest.
+		{From: "dragons_lair.fork1", To: "dragons_lair.ash_bridge", Lock: LockNone, Weight: 1},
+		{From: "dragons_lair.fork1", To: "dragons_lair.treasure_vault",
+			Lock: LockPerception, LockData: map[string]any{"dc": 15},
+			Hint: "a draft from a side passage — and the dull glint of gold beyond it", Weight: 2},
+		{From: "dragons_lair.ash_bridge", To: "dragons_lair.wyrmlings_nest", Lock: LockNone},
+		{From: "dragons_lair.treasure_vault", To: "dragons_lair.wyrmlings_nest", Lock: LockNone},
+		{From: "dragons_lair.wyrmlings_nest", To: "dragons_lair.fork2", Lock: LockNone},
+		// Fork2 — capstone 3-way.
+		{From: "dragons_lair.fork2", To: "dragons_lair.direct_confrontation", Lock: LockNone, Weight: 1},
+		{From: "dragons_lair.fork2", To: "dragons_lair.dragon_bargain",
+			Lock: LockStatCheck, LockData: map[string]any{"stat": "CHA", "dc": 16},
+			Hint: "Infernax speaks. The voice fills the chamber. You could speak back.", Weight: 2},
+		{From: "dragons_lair.fork2", To: "dragons_lair.hoard_pillar",
+			Lock: LockPerception, LockData: map[string]any{"dc": 17},
+			Hint: "a single coin standing on edge — a draft, not a tremor", Weight: 3},
+		{From: "dragons_lair.direct_confrontation", To: "dragons_lair.boss", Lock: LockNone},
+		{From: "dragons_lair.dragon_bargain", To: "dragons_lair.boss", Lock: LockNone},
+		{From: "dragons_lair.hoard_pillar", To: "dragons_lair.boss", Lock: LockNone},
+	}
+	return BuildGraph(ZoneDragonsLair, nodes, edges)
+}
+
+func init() {
+	registerZoneGraph(zoneDragonsLairGraph())
+}

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)
+	}
+}