Branching zones G9a: remove GOGOBEE_BRANCHING_ZONES gate

All 9 zones have hand-authored graphs (G8a–G8i), so the POC gate has
served its purpose. Make graph mode the only runtime path:

- Drop branchingZonesEnabled() and the os import in zone_graph_nav.go.
- Inline the gate-on branches in zoneCmdMap, zoneCmdAdvance,
  CurrentRoomType, startZoneRun, and the expedition map renderer.
- Keep the legacy linear functions (markRoomCleared, renderZoneMap,
  generateRoomSequence) standing — their tests still exercise them and
  they'll retire alongside current_room / room_seq_json in G9b.
- Strip gate test (TestBranchingZonesGate, TestCurrentRoomType_GateOff)
  and t.Setenv calls from the surviving graph tests.

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

internal/plugin/dnd_expedition_map.go

@@ -113,19 +113,24 @@ func (p *AdventurePlugin) handleExpeditionMapCmd(ctx MessageContext, _ string) e
 	// Per-run room map. The expedition's zone run is the per-region
 	// dungeon instance; for single-region zones it's the only run.
 	run, _ := getActiveZoneRun(ctx.Sender)
-	if run != nil && len(run.RoomSeq) > 0 {
-		cleared := map[int]bool{}
-		for _, r := range run.RoomsCleared {
-			cleared[r] = true
-		}
-		b.WriteString("```\n")
-		b.WriteString(renderZoneMap(run.RoomSeq, run.CurrentRoom, cleared))
-		b.WriteString("\n```\n")
-		b.WriteString("_E=Entry  ?=Exploration  T=Trap  ★=Elite  ☠=Boss · ✓ cleared  ▶ here  · pending_")
-		if chain != "" {
-			b.WriteString("\n_Regions: ")
-			b.WriteString(renderRegionLegend(exp))
-			b.WriteString(" · ⛺ base camp pitched_")
+	if run != nil {
+		if g, ok := loadZoneGraph(run.ZoneID); ok {
+			b.WriteString("```\n")
+			b.WriteString(renderZoneGraphMap(g, run))
+			b.WriteString("\n```\n")
+			b.WriteString("_E=Entry  ?=Exploration  T=Trap  ★=Elite  ☠=Boss  ⚿=Secret · ✓ cleared  ▶ here  · pending  ╳ locked_")
+			if chain != "" {
+				b.WriteString("\n_Regions: ")
+				b.WriteString(renderRegionLegend(exp))
+				b.WriteString(" · ⛺ base camp pitched_")
+			}
+		} else {
+			b.WriteString("_(no room layout — between rooms or pre-entry)_")
+			if chain != "" {
+				b.WriteString("\n_Regions: ")
+				b.WriteString(renderRegionLegend(exp))
+				b.WriteString(" · ⛺ base camp pitched_")
+			}
 		}
 	} else {
 		b.WriteString("_(no room layout — between rooms or pre-entry)_")

internal/plugin/dnd_zone_cmd.go

@@ -288,14 +288,13 @@ func (p *AdventurePlugin) zoneCmdMap(ctx MessageContext) error {
 	zone := zoneOrFallback(run.ZoneID)
 	var b strings.Builder
 	b.WriteString(fmt.Sprintf("**%s — Map**\n```\n", zone.Display))
-	if branchingZonesEnabled() {
-		if g, ok := loadZoneGraph(run.ZoneID); ok {
-			b.WriteString(renderZoneGraphMap(g, run))
-			b.WriteString("\n```\n")
-			b.WriteString("_E=Entry  ?=Exploration  T=Trap  ★=Elite  ☠=Boss  ⚿=Secret · ✓ cleared  ▶ here  · pending  ╳ locked_")
-			return p.SendDM(ctx.Sender, b.String())
-		}
+	if g, ok := loadZoneGraph(run.ZoneID); ok {
+		b.WriteString(renderZoneGraphMap(g, run))
+		b.WriteString("\n```\n")
+		b.WriteString("_E=Entry  ?=Exploration  T=Trap  ★=Elite  ☠=Boss  ⚿=Secret · ✓ cleared  ▶ here  · pending  ╳ locked_")
+		return p.SendDM(ctx.Sender, b.String())
 	}
+	// No registered graph (defensive — every zone has one post-G8).
 	cleared := map[int]bool{}
 	for _, r := range run.RoomsCleared {
 		cleared[r] = true
@@ -415,60 +414,18 @@ func (p *AdventurePlugin) zoneCmdAdvance(ctx MessageContext) error {
 		return p.streamOrSend(ctx.Sender, preStream, intro, phases, outcome)
 	}
 
-	// Graph-mode (POC gate): clear the current room, then either auto-advance
-	// down a single edge, surface a fork prompt for 2+ edges, or complete the
-	// run when there are 0 outgoing edges. Legacy linear path stays on
-	// markRoomCleared so non-gated deployments are bit-identical to G4.
-	if branchingZonesEnabled() {
-		c, cerr := LoadDnDCharacter(ctx.Sender)
-		if cerr != nil {
-			return p.SendDM(ctx.Sender, "Couldn't load character: "+cerr.Error())
-		}
-		next, forkMsg, complete, gerr := p.advanceTransitionGraph(run, zone, c)
-		if gerr != nil {
-			return p.SendDM(ctx.Sender, "Couldn't advance: "+gerr.Error())
-		}
-		if complete {
-			_, _ = applyMoodEvent(run.RunID, MoodEventZoneComplete)
-			var b strings.Builder
-			if outcome != "" {
-				b.WriteString(outcome)
-				b.WriteString("\n\n")
-			}
-			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")
-			}
-			if granted := p.rollZoneLoot(ctx.Sender, run, zone); len(granted) > 0 {
-				b.WriteString("**Loot:**\n")
-				for _, id := range granted {
-					b.WriteString("• " + id + "\n")
-				}
-			}
-			return p.streamOrSend(ctx.Sender, preStream, intro, phases, b.String())
-		}
-		if forkMsg != "" {
-			var b strings.Builder
-			if outcome != "" {
-				b.WriteString(outcome)
-				b.WriteString("\n\n")
-			}
-			b.WriteString(fmt.Sprintf("✓ Cleared room %d (%s).\n\n", prevIdx+1, prettyRoomType(prev)))
-			b.WriteString(forkMsg)
-			return p.streamOrSend(ctx.Sender, preStream, intro, phases, b.String())
-		}
-		// Single-edge auto-advance — fall through to the shared next-room
-		// teaser using the resolved next room type.
-		return p.streamOrSend(ctx.Sender, preStream, intro, phases,
-			p.formatNextRoomMessage(run, zone, prev, prevIdx, outcome, next))
+	// Graph-mode advance (G9a — only mode now): clear the current room,
+	// then either auto-advance down a single edge, surface a fork prompt
+	// for 2+ edges, or complete the run when there are 0 outgoing edges.
+	c, cerr := LoadDnDCharacter(ctx.Sender)
+	if cerr != nil {
+		return p.SendDM(ctx.Sender, "Couldn't load character: "+cerr.Error())
 	}
-
-	next, err := markRoomCleared(run.RunID)
-	if err != nil {
-		return p.SendDM(ctx.Sender, "Couldn't advance: "+err.Error())
+	next, forkMsg, complete, gerr := p.advanceTransitionGraph(run, zone, c)
+	if gerr != nil {
+		return p.SendDM(ctx.Sender, "Couldn't advance: "+gerr.Error())
 	}
-	if next == "" {
+	if complete {
 		_, _ = applyMoodEvent(run.RunID, MoodEventZoneComplete)
 		var b strings.Builder
 		if outcome != "" {
@@ -488,7 +445,16 @@ func (p *AdventurePlugin) zoneCmdAdvance(ctx MessageContext) error {
 		}
 		return p.streamOrSend(ctx.Sender, preStream, intro, phases, b.String())
 	}
-
+	if forkMsg != "" {
+		var b strings.Builder
+		if outcome != "" {
+			b.WriteString(outcome)
+			b.WriteString("\n\n")
+		}
+		b.WriteString(fmt.Sprintf("✓ Cleared room %d (%s).\n\n", prevIdx+1, prettyRoomType(prev)))
+		b.WriteString(forkMsg)
+		return p.streamOrSend(ctx.Sender, preStream, intro, phases, b.String())
+	}
 	return p.streamOrSend(ctx.Sender, preStream, intro, phases,
 		p.formatNextRoomMessage(run, zone, prev, prevIdx, outcome, next))
 }

internal/plugin/dnd_zone_run.go

@@ -85,21 +85,17 @@ func (r *DungeonRun) IsActive() bool {
 }
 
 // CurrentRoomType returns the type of the room the player is currently
-// standing in. In gated graph mode (GOGOBEE_BRANCHING_ZONES=1) with a
-// hand-authored ZoneGraph registered for the run's zone, the live
-// CurrentNode's kind is authoritative — that's the only way side paths
-// (e.g. the Crypt of Valdris secret chamber) resolve to the right
-// room-type when the player diverges from the canonical RoomSeq. The
-// legacy RoomSeq fallback covers gate-off runs and runs in zones whose
-// graph is still the linear-compiled one. Returns "" if no resolution
-// is possible.
+// standing in. The live CurrentNode's kind is authoritative — that's
+// the only way side paths (e.g. the Crypt of Valdris secret chamber)
+// resolve to the right room-type when the player diverges from the
+// canonical RoomSeq. The legacy RoomSeq fallback covers in-flight runs
+// from before the G4 dual-write deploy that lack a CurrentNode entry.
+// Returns "" if no resolution is possible.
 func (r *DungeonRun) CurrentRoomType() RoomType {
-	if branchingZonesEnabled() && r.CurrentNode != "" {
-		if _, authored := zoneGraphRegistry[r.ZoneID]; authored {
-			if g, ok := loadZoneGraph(r.ZoneID); ok {
-				if n, exists := g.Nodes[r.CurrentNode]; exists {
-					return nodeKindToRoomType(n.Kind)
-				}
+	if r.CurrentNode != "" {
+		if g, ok := loadZoneGraph(r.ZoneID); ok {
+			if n, exists := g.Nodes[r.CurrentNode]; exists {
+				return nodeKindToRoomType(n.Kind)
 			}
 		}
 	}
@@ -228,15 +224,12 @@ func startZoneRun(userID id.UserID, zoneID ZoneID, dndLevel int, rng *rand.Rand)
 	}
 	// G4 dual-write: persist the entry node id and seed visited_nodes
 	// with it, so navigation surfaces in G5 can read graph state without
-	// further migration. G7: when graph mode is on AND the zone has a
-	// hand-authored graph, start at that graph's Entry node so the player
-	// actually traverses the authored topology rather than falling off
-	// into the legacy `<zone>.r1` namespace.
+	// further migration. New runs always start at the registered graph's
+	// Entry node; only zones that lack a registered graph (none, post-G8)
+	// would fall back to the legacy linear `<zone>.r1` namespace.
 	entryNode := deriveLegacyNodeID(zoneID, 0)
-	if branchingZonesEnabled() {
-		if g, ok := zoneGraphRegistry[zoneID]; ok {
-			entryNode = g.Entry
-		}
+	if g, ok := zoneGraphRegistry[zoneID]; ok {
+		entryNode = g.Entry
 	}
 	visitedJSON, _ := json.Marshal([]string{entryNode})
 	run.CurrentNode = entryNode

internal/plugin/zone_graph_crypt_valdris.go

@@ -14,9 +14,6 @@ package plugin
 //
 // Two paths to the boss (main_hall vs side_chapel); secret_chamber
 // dangles off side_chapel for an extra Perception gate with loot.
-// Registration is unconditional — the runtime gate
-// (GOGOBEE_BRANCHING_ZONES) decides whether new runs adopt this graph
-// or stay on the legacy linear template.
 
 func zoneCryptValdrisGraph() ZoneGraph {
 	nodes := []ZoneNode{

internal/plugin/zone_graph_crypt_valdris_test.go

@@ -87,14 +87,12 @@ func TestCryptValdrisGraph_SecretGated(t *testing.T) {
 	}
 }
 
-// TestCurrentRoomType_GraphAuthored verifies that in gated graph mode,
-// CurrentRoomType resolves via the registered graph's node kind rather
-// than the legacy RoomSeq lookup. This is what makes side_path nodes
-// (e.g. the secret_chamber) resolve to the right RoomType when the
-// player diverges from the canonical RoomSeq layout.
+// TestCurrentRoomType_GraphAuthored verifies that CurrentRoomType
+// resolves via the registered graph's node kind rather than the legacy
+// RoomSeq lookup. This is what makes side_path nodes (e.g. the
+// secret_chamber) resolve to the right RoomType when the player
+// diverges from the canonical RoomSeq layout.
 func TestCurrentRoomType_GraphAuthored(t *testing.T) {
-	t.Setenv("GOGOBEE_BRANCHING_ZONES", "1")
-
 	// Mismatched RoomSeq vs. live CurrentNode: CurrentRoom=2 would land
 	// on RoomTrap in the legacy fallback, but the graph node kind is
 	// Elite (main_hall). Graph wins.
@@ -121,18 +119,3 @@ func TestCurrentRoomType_GraphAuthored(t *testing.T) {
 	}
 }
 
-// TestCurrentRoomType_GateOffUsesRoomSeq asserts the legacy behavior is
-// untouched when the gate is off: RoomSeq[CurrentRoom] is authoritative
-// even though Crypt of Valdris has a registered graph.
-func TestCurrentRoomType_GateOffUsesRoomSeq(t *testing.T) {
-	t.Setenv("GOGOBEE_BRANCHING_ZONES", "")
-	run := &DungeonRun{
-		ZoneID:      ZoneCryptValdris,
-		CurrentRoom: 2,
-		CurrentNode: "crypt_valdris.main_hall",
-		RoomSeq:     []RoomType{RoomEntry, RoomExploration, RoomTrap, RoomElite, RoomBoss},
-	}
-	if got := run.CurrentRoomType(); got != RoomTrap {
-		t.Errorf("gate off: got %s, want %s (RoomSeq lookup)", got, RoomTrap)
-	}
-}

internal/plugin/zone_graph_map.go

@@ -2,12 +2,12 @@ package plugin
 
 // Phase G6 — graph-aware !zone map renderer.
 //
-// Replaces the linear renderZoneMap() output when GOGOBEE_BRANCHING_ZONES
-// is on. Walks the registered (or legacy-compiled) ZoneGraph in BFS
-// order rooted at Entry, lays nodes out by PosX/PosY, and prints a
-// horizontal glyph row per layer with a status row underneath. Locked
-// outgoing edges show as `╳`; secret nodes stay hidden until the
-// player has visited them (prevents spoilers from `!zone map`).
+// Replaces the linear renderZoneMap() output. Walks the registered
+// (or legacy-compiled) ZoneGraph in BFS order rooted at Entry, lays
+// nodes out by PosX/PosY, and prints a horizontal glyph row per layer
+// with a status row underneath. Locked outgoing edges show as `╳`;
+// secret nodes stay hidden until the player has visited them
+// (prevents spoilers from `!zone map`).
 
 import (
 	"fmt"

internal/plugin/zone_graph_nav.go

@@ -8,28 +8,19 @@ package plugin
 // consumes the choice, validates the chosen edge is unlocked, and
 // advances the run state to the chosen node.
 //
-// Behavior is gated by GOGOBEE_BRANCHING_ZONES=1 during the POC week
-// (plan §G5 / §9.5). With the gate off, !zone advance still uses the
-// linear markRoomCleared path and forks never fire — even on zones
-// that have a hand-authored graph registered.
+// G9a retired the GOGOBEE_BRANCHING_ZONES POC gate: graph mode is the
+// only runtime path now that all 9 zones have hand-authored graphs.
 
 import (
 	"crypto/sha1"
 	"encoding/binary"
 	"encoding/json"
 	"fmt"
-	"os"
 	"strings"
 
 	"gogobee/internal/db"
 )
 
-// branchingZonesEnabled — POC gate. Default off. Operator flips it for
-// the POC soak week, then it's removed in G9.
-func branchingZonesEnabled() bool {
-	return os.Getenv("GOGOBEE_BRANCHING_ZONES") == "1"
-}
-
 // pendingFork is the typed shape of dnd_zone_run.node_choices when the
 // player is paused at a fork. Persisted as JSON inside the
 // map[string]any NodeChoices column; helpers below round-trip via JSON

internal/plugin/zone_graph_nav_test.go

@@ -241,17 +241,3 @@ func TestNodeKindToRoomType(t *testing.T) {
 	}
 }
 
-func TestBranchingZonesGate(t *testing.T) {
-	t.Setenv("GOGOBEE_BRANCHING_ZONES", "")
-	if branchingZonesEnabled() {
-		t.Error("gate should be off when env empty")
-	}
-	t.Setenv("GOGOBEE_BRANCHING_ZONES", "1")
-	if !branchingZonesEnabled() {
-		t.Error("gate should be on when env=1")
-	}
-	t.Setenv("GOGOBEE_BRANCHING_ZONES", "0")
-	if branchingZonesEnabled() {
-		t.Error("gate should be off when env=0")
-	}
-}