Branching zones G6: dependent surfaces re-keyed on graph nodes

- Harvest tables (expedition + standalone) now keyed by node_id; legacy
  room-idx entries auto-migrate via read-fallback + drop-on-save.
- Narration salts swapped from run.CurrentRoom to narrationCadence(run)
  (= len(visited_nodes)-1) so flavor pickers survive G9 column drop.
- !zone map renders the graph (BFS by PosX/PosY) when the gate is on:
  ✓/▶/· status, ╳ for locked-only edges, secrets hidden until visited.
- Region-boundary hook in graph advance/!zone go updates expedition
  CurrentRegion + visited list when from/to nodes differ — without
  burning supplies or retiring runs (the graph IS the run state).

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

internal/plugin/zone_graph_map_test.go

@@ -0,0 +1,81 @@
+package plugin
+
+import (
+	"strings"
+	"testing"
+)
+
+// TestRenderZoneGraphMap_LinearLooksFamiliar exercises the linear-graph
+// case so the new renderer doesn't regress the legacy single-row look.
+func TestRenderZoneGraphMap_LinearLooksFamiliar(t *testing.T) {
+	g := BuildLinearGraph(ZoneGoblinWarrens, []ZoneNodeKind{
+		NodeKindEntry, NodeKindExploration, NodeKindTrap, NodeKindBoss,
+	})
+	run := &DungeonRun{
+		ZoneID:       ZoneGoblinWarrens,
+		CurrentNode:  "goblin_warrens.r2",
+		VisitedNodes: []string{"goblin_warrens.r1", "goblin_warrens.r2"},
+	}
+	got := renderZoneGraphMap(g, run)
+	// Top row should contain glyphs in order.
+	if !strings.Contains(got, "E──?──T──☠") {
+		t.Errorf("missing linear glyph row in:\n%s", got)
+	}
+	// Status row: first cleared, second current, rest pending.
+	if !strings.Contains(got, "✓") || !strings.Contains(got, "▶") || !strings.Contains(got, "·") {
+		t.Errorf("missing status markers in:\n%s", got)
+	}
+}
+
+// TestRenderZoneGraphMap_HidesUnvisitedSecrets confirms the spoiler
+// guard: secret nodes don't render until the player has reached them.
+func TestRenderZoneGraphMap_HidesUnvisitedSecrets(t *testing.T) {
+	nodes := []ZoneNode{
+		{NodeID: "z.entry", Kind: NodeKindEntry, IsEntry: true, PosX: 0},
+		{NodeID: "z.boss", Kind: NodeKindBoss, IsBoss: true, PosX: 1},
+		{NodeID: "z.secret", Kind: NodeKindSecret, PosX: 1, PosY: 1},
+	}
+	edges := []ZoneEdge{
+		{From: "z.entry", To: "z.boss"},
+		{From: "z.entry", To: "z.secret", Lock: LockPerception, LockData: map[string]any{"dc": 12}},
+	}
+	g := BuildGraph("test_zone", nodes, edges)
+
+	hidden := renderZoneGraphMap(g, &DungeonRun{
+		CurrentNode:  "z.entry",
+		VisitedNodes: []string{"z.entry"},
+	})
+	if strings.Contains(hidden, "⚿") {
+		t.Errorf("unvisited secret should not render, got:\n%s", hidden)
+	}
+	// Once visited, the glyph appears.
+	revealed := renderZoneGraphMap(g, &DungeonRun{
+		CurrentNode:  "z.secret",
+		VisitedNodes: []string{"z.entry", "z.secret"},
+	})
+	if !strings.Contains(revealed, "⚿") {
+		t.Errorf("visited secret should render, got:\n%s", revealed)
+	}
+}
+
+// TestRenderZoneGraphMap_LockedEdgeRenderedAsCross verifies locked-only
+// approaches show ╳ instead of ──.
+func TestRenderZoneGraphMap_LockedEdgeRenderedAsCross(t *testing.T) {
+	nodes := []ZoneNode{
+		{NodeID: "z.entry", Kind: NodeKindEntry, IsEntry: true, PosX: 0},
+		{NodeID: "z.gate", Kind: NodeKindExploration, PosX: 1},
+		{NodeID: "z.boss", Kind: NodeKindBoss, IsBoss: true, PosX: 2},
+	}
+	edges := []ZoneEdge{
+		{From: "z.entry", To: "z.gate", Lock: LockKey, LockData: map[string]any{"key_id": "rune"}},
+		{From: "z.gate", To: "z.boss"},
+	}
+	g := BuildGraph("test_zone_locked", nodes, edges)
+	got := renderZoneGraphMap(g, &DungeonRun{
+		CurrentNode:  "z.entry",
+		VisitedNodes: []string{"z.entry"},
+	})
+	if !strings.Contains(got, "╳") {
+		t.Errorf("locked edge should render as ╳, got:\n%s", got)
+	}
+}