R1: split "where am I" from "how far have I walked"

Backtracking (revisit R2) breaks the assumption every zone-run caller
quietly relied on: that CurrentRoom == len(VisitedNodes)-1. Position and
progress have been the same number only because navigation was
forward-only.

Split them. CurrentRoom is now the first-entry index of CurrentNode in
VisitedNodes -- the room number the player was shown on the way in, and
the salt that enemy/trap/harvest/encounter keys hash. A revisited room
therefore resolves to the same room. RoomsTraversed is a new monotonic
step counter, persisted, backfilled from visited_nodes for in-flight rows.

The audit found only two progress-shaped reads. narrationCadence moves to
RoomsTraversed so a backtracking player draws fresh flavor rather than
replaying the entry-room lines. The other was a latent bug: zoneCmdGo
labelled the room it moved into as CurrentRoom+1, which is only correct at
the frontier; advanceZoneRunNode now returns the true path index.

VisitedNodes becomes an ordered set and RoomsCleared becomes idempotent --
both no-ops while navigation is forward-only, both load-bearing after R2.

No player-visible behavior change. Nothing to route off RoomsTraversed for
threat/SU: verified at HEAD that movement charges neither. Threat comes
from combat, supplies burn per day. The revisit plan's cost model claimed
otherwise and has been corrected -- R2's "discount" is really a net-new
cost decision.

internal/db/db.go

@@ -345,6 +345,13 @@ func runMigrations(d *sql.DB) error {
 		// needs no bootstrap backfill.
 		`ALTER TABLE adventure_inventory ADD COLUMN temper INTEGER NOT NULL DEFAULT 0`,
 		`ALTER TABLE magic_item_equipped ADD COLUMN temper INTEGER NOT NULL DEFAULT 0`,
+		// Revisit R1 (gogobee_revisit_plan.md §R1). Until now "how far along
+		// is this run" and "which room am I standing in" were the same number,
+		// both read off len(visited_nodes). Backtracking splits them: the
+		// path index stops being monotonic, so effort gets its own counter.
+		// DEFAULT 0 is wrong for in-flight rows — bootstrapRoomsTraversed
+		// backfills them from visited_nodes.
+		`ALTER TABLE dnd_zone_run ADD COLUMN rooms_traversed INTEGER NOT NULL DEFAULT 0`,
 	}
 	for _, stmt := range columnMigrations {
 		if _, err := d.Exec(stmt); err != nil {

internal/plugin/adventure.go

@@ -177,6 +177,7 @@ func (p *AdventurePlugin) Init() error {
 	// through the L4-L5h dual-write soak (fresh deploys, restored backups).
 	bootstrapPlayerMetaFromLegacy()
 	bootstrapRestoreExpeditionStreakDecay()
+	bootstrapRoomsTraversed()
 
 	// Rehydrate DM room mappings for existing characters
 	chars, err := loadAllAdvCharacters()

internal/plugin/bootstrap_rooms_traversed.go

@@ -0,0 +1,35 @@
+package plugin
+
+import (
+	"log/slog"
+
+	"gogobee/internal/db"
+)
+
+// bootstrapRoomsTraversed backfills dnd_zone_run.rooms_traversed for rows
+// that predate the revisit R1 column. Before R1 the step counter was implicit
+// — len(visited_nodes) — because navigation was forward-only, so replaying
+// that identity is an exact reconstruction, not an estimate.
+//
+// The ALTER lands DEFAULT 0, which would tell an in-flight run it has walked
+// nowhere: ambient narration cadence would reset to the entry-room line and
+// R2's revisit preflight would read a fresh run. Hence the backfill.
+//
+// Idempotent, and safe to run against live rows: every row written after R1
+// inserts rooms_traversed >= 1 (the entry node counts as one traversal), so
+// `rooms_traversed = 0` uniquely identifies a row this has not yet touched.
+// Kept in-tree permanently — a fresh deploy restoring an old backup needs it
+// (feedback_loader_rewire_needs_bootstrap).
+func bootstrapRoomsTraversed() {
+	res, err := db.Get().Exec(`
+		UPDATE dnd_zone_run
+		   SET rooms_traversed = MAX(json_array_length(visited_nodes), 1)
+		 WHERE rooms_traversed = 0`)
+	if err != nil {
+		slog.Error("bootstrap: rooms_traversed backfill failed", "err", err)
+		return
+	}
+	if n, _ := res.RowsAffected(); n > 0 {
+		slog.Warn("bootstrap: rooms_traversed backfilled from visited_nodes", "rows", n)
+	}
+}

internal/plugin/dnd_expedition_cmd.go

@@ -692,7 +692,7 @@ func (p *AdventurePlugin) autoPickStaleFork(exp *Expedition, run *DungeonRun, pf
 	if chosen == nil {
 		return false // nothing unlocked — leave it for the player / reaper
 	}
-	if err := advanceZoneRunNode(run.RunID, chosen.To); err != nil {
+	if _, err := advanceZoneRunNode(run.RunID, chosen.To); err != nil {
 		slog.Warn("expedition: auto-pick stale fork",
 			"user", run.UserID, "run", run.RunID, "err", err)
 		return false

internal/plugin/dnd_zone_cmd_graph.go

@@ -62,7 +62,7 @@ func (p *AdventurePlugin) advanceTransitionGraph(run *DungeonRun, zone ZoneDefin
 	if len(choices) == 1 && len(unlocked) == 1 {
 		// Plain auto-advance — no fork to prompt for.
 		chosen := choices[0]
-		if aerr := advanceZoneRunNode(run.RunID, chosen.To); aerr != nil {
+		if _, aerr := advanceZoneRunNode(run.RunID, chosen.To); aerr != nil {
 			err = aerr
 			return
 		}
@@ -184,7 +184,8 @@ func (p *AdventurePlugin) zoneCmdGo(ctx MessageContext, rest string) error {
 	if cerr != nil {
 		return p.SendDM(ctx.Sender, cerr.Error())
 	}
-	if aerr := advanceZoneRunNode(run.RunID, chosen.To); aerr != nil {
+	nextIdx, aerr := advanceZoneRunNode(run.RunID, chosen.To)
+	if aerr != nil {
 		return p.SendDM(ctx.Sender, "Couldn't advance: "+aerr.Error())
 	}
 	markActedToday(ctx.Sender)
@@ -194,7 +195,6 @@ func (p *AdventurePlugin) zoneCmdGo(ctx MessageContext, rest string) error {
 	nextNode := g.Nodes[chosen.To]
 	fireGraphRegionTransition(run.UserID, fromNode, nextNode)
 	nextRoom := nodeKindToRoomType(nextNode.Kind)
-	nextIdx := run.CurrentRoom + 1
 	var b strings.Builder
 	if kind := autoBreakCampOnMove(ctx.Sender); kind != "" {
 		b.WriteString(fmt.Sprintf("⛺ Camp struck (**%s**) — the party moved on.\n\n", kind))

internal/plugin/dnd_zone_narration.go

@@ -330,16 +330,26 @@ func eliteRoomEntryLine(zoneID ZoneID, runID string, roomIdx int) string {
 	return "🎭 **TwinBee:** " + line
 }
 
-// narrationCadence returns the salt index used to seed narration
-// pickers — the count of nodes visited so far (0-based, matching the
-// pre-G6 CurrentRoom semantics). Both linear-mode and graph-mode
-// advance bump len(VisitedNodes) in lockstep with CurrentRoom, so this
-// preserves existing pick determinism while letting G9 drop the legacy
-// current_room column without re-keying every flavor pool seed.
+// narrationCadence returns the salt index used to seed narration pickers —
+// the number of rooms walked so far, 0-based. This is a *progress* read, not
+// a position read (revisit R1's audit split): flavor should keep moving
+// forward as the player does, so a backtrack draws fresh lines rather than
+// replaying the ones they already read on the way in.
+//
+// Forward-only runs have RoomsTraversed == len(VisitedNodes), so this stays
+// numerically identical to the pre-R1 derivation and every existing pick
+// keeps landing on the same line. It is stable while the player stands
+// still, which is what lets a re-read of `!status` print the same prose.
+//
+// The len(VisitedNodes) fallback covers rows that predate the R1 column and
+// have yet to be swept by bootstrapRoomsTraversed.
 func narrationCadence(run *DungeonRun) int {
 	if run == nil {
 		return 0
 	}
+	if run.RoomsTraversed > 0 {
+		return run.RoomsTraversed - 1
+	}
 	if n := len(run.VisitedNodes); n > 0 {
 		return n - 1
 	}

internal/plugin/dnd_zone_run.go

@@ -76,6 +76,14 @@ type DungeonRun struct {
 	CurrentNode   string
 	VisitedNodes  []string
 	NodeChoices   map[string]any
+
+	// Revisit R1 — monotonic count of node entries, including the entry
+	// room. Distinct from CurrentRoom: CurrentRoom answers "where am I on
+	// the path" and moves backwards when the player backtracks, while
+	// RoomsTraversed answers "how much walking has this run cost" and only
+	// ever climbs. Forward-only navigation keeps them locked together at
+	// RoomsTraversed == CurrentRoom+1; revisit is what pulls them apart.
+	RoomsTraversed int
 }
 
 // IsActive reports whether this run is still ongoing (not boss-defeated,
@@ -244,12 +252,16 @@ func startZoneRun(userID id.UserID, zoneID ZoneID, dndLevel int, rng *rand.Rand)
 	run.CurrentNode = entryNode
 	run.VisitedNodes = []string{entryNode}
 	run.NodeChoices = map[string]any{}
+	// Standing in the entry room is one traversal — the player walked in.
+	// Starting at 1 also keeps `rooms_traversed = 0` free as the
+	// "never backfilled" sentinel bootstrapRoomsTraversed keys on.
+	run.RoomsTraversed = 1
 	if _, err := db.Get().Exec(`
 		INSERT INTO dnd_zone_run
 			(run_id, user_id, zone_id, total_rooms,
 			 rooms_cleared, gm_mood,
-			 current_node, visited_nodes, node_choices)
-		VALUES (?, ?, ?, ?, '[]', ?, ?, ?, '{}')`,
+			 current_node, visited_nodes, node_choices, rooms_traversed)
+		VALUES (?, ?, ?, ?, '[]', ?, ?, ?, '{}', 1)`,
 		run.RunID, run.UserID, string(zoneID), run.TotalRooms, startMood,
 		entryNode, string(visitedJSON),
 	); err != nil {
@@ -272,7 +284,7 @@ func getActiveZoneRun(userID id.UserID) (*DungeonRun, error) {
 		SELECT run_id, user_id, zone_id, total_rooms,
 		       rooms_cleared, boss_defeated, abandoned,
 		       loot_collected, gm_mood, started_at, last_action_at, completed_at,
-		       current_node, visited_nodes, node_choices
+		       current_node, visited_nodes, node_choices, rooms_traversed
 		  FROM dnd_zone_run
 		 WHERE user_id = ?
 		   AND completed_at IS NULL
@@ -312,7 +324,7 @@ func getZoneRun(runID string) (*DungeonRun, error) {
 		SELECT run_id, user_id, zone_id, total_rooms,
 		       rooms_cleared, boss_defeated, abandoned,
 		       loot_collected, gm_mood, started_at, last_action_at, completed_at,
-		       current_node, visited_nodes, node_choices
+		       current_node, visited_nodes, node_choices, rooms_traversed
 		  FROM dnd_zone_run WHERE run_id = ?`, runID)
 	r, err := scanZoneRun(row)
 	if errors.Is(err, sql.ErrNoRows) {
@@ -343,7 +355,7 @@ func scanZoneRun(row scanner) (*DungeonRun, error) {
 		&r.RunID, &r.UserID, &zoneID, &r.TotalRooms,
 		&clearedJSON, &bossDefeatedI, &abandonedI,
 		&lootJSON, &r.DMMood, &r.StartedAt, &r.LastActionAt, &completedAtRaw,
-		&currentNode, &visitedJSON, &choicesJSON,
+		&currentNode, &visitedJSON, &choicesJSON, &r.RoomsTraversed,
 	); err != nil {
 		return nil, err
 	}
@@ -390,14 +402,16 @@ func scanZoneRun(row scanner) (*DungeonRun, error) {
 		r.NodeChoices = map[string]any{}
 	}
 	r.CurrentNode = currentNode
-	// G9b: CurrentRoom is now derived from VisitedNodes — no longer
-	// persisted in current_room. The downstream callers that key on
-	// CurrentRoom (combat enemy/trap salts, status renders, harvest
-	// keys) stay numerically identical to the dual-write era because
-	// VisitedNodes was bumped in lockstep with current_room.
-	if n := len(r.VisitedNodes); n > 0 {
-		r.CurrentRoom = n - 1
-	}
+	// G9b: CurrentRoom is derived from VisitedNodes — no longer persisted
+	// in current_room. Revisit R1 re-derives it as the *first-entry index
+	// of CurrentNode* rather than len(VisitedNodes)-1. The two agree for
+	// every forward-only run (each advance appends the node it moves to,
+	// so the newest node is always the current one), but they diverge the
+	// moment a player backtracks. Keying on the node — not the tail — is
+	// what makes a revisited room resolve to its original identity: the
+	// enemy/trap salts, harvest keys and encounter IDs downstream all
+	// hash CurrentRoom, so room 3 must stay room 3 on the way back.
+	r.CurrentRoom = pathIndexOf(r.VisitedNodes, r.CurrentNode)
 	if r.CurrentNode == "" {
 		// Defensive: a row from before the G4 dual-write deploy that
 		// somehow survived 24h inactivity timeouts. Pin to the linear
@@ -407,6 +421,53 @@ func scanZoneRun(row scanner) (*DungeonRun, error) {
 	return &r, nil
 }
 
+// appendVisited records a node entry in first-entry order. A node already
+// in the path is not re-appended: VisitedNodes is an ordered *set*, and the
+// player's room numbers must not renumber themselves when they walk back
+// through a room they've already seen. The step cost of that walk is
+// carried by rooms_traversed, not by this slice.
+func appendVisited(visited []string, node string) []string {
+	for _, n := range visited {
+		if n == node {
+			return visited
+		}
+	}
+	return append(visited, node)
+}
+
+// appendClearedRoom marks a room index resolved. Idempotent: walking out of
+// a room a second time doesn't re-append. "Cleared" is a sticky property of
+// the room, not a count of exits — re-appending would let a backtracking
+// player inflate RoomsCleared past TotalRooms and skew every "N/M rooms"
+// render that reads its length.
+func appendClearedRoom(cleared []int, room int) []int {
+	for _, r := range cleared {
+		if r == room {
+			return cleared
+		}
+	}
+	return append(cleared, room)
+}
+
+// pathIndexOf returns the first-entry index of node within visited — the
+// 0-based room number the player sees in `!map`'s Path strip. Revisits do
+// not append, so a node's index is stable for the life of the run.
+//
+// A node missing from visited means a row whose current_node was hot-swapped
+// in without a matching visit record (pre-G4 rows, defensive only). Fall back
+// to the tail, which is what the pre-R1 derivation would have produced.
+func pathIndexOf(visited []string, node string) int {
+	for i, n := range visited {
+		if n == node {
+			return i
+		}
+	}
+	if n := len(visited); n > 0 {
+		return n - 1
+	}
+	return 0
+}
+
 // deriveLegacyNodeID returns the node id a linear graph would assign
 // to position roomIdx (0-based) for the given zone. Mirrors
 // BuildLinearGraph's "<zone>.r<n>" scheme so hot-swapped rows align
@@ -439,7 +500,7 @@ func markRoomCleared(runID string) (RoomType, error) {
 	if !ok {
 		return "", fmt.Errorf("no graph for zone %q", r.ZoneID)
 	}
-	cleared := append(r.RoomsCleared, r.CurrentRoom)
+	cleared := appendClearedRoom(r.RoomsCleared, r.CurrentRoom)
 	clearedJSON, _ := json.Marshal(cleared)
 
 	edges := g.outgoingEdges(r.CurrentNode)
@@ -461,13 +522,14 @@ func markRoomCleared(runID string) (RoomType, error) {
 		return "", nil
 	}
 	nextNode := edges[0].To
-	visited := append(r.VisitedNodes, nextNode)
+	visited := appendVisited(r.VisitedNodes, nextNode)
 	visitedJSON, _ := json.Marshal(visited)
 	if _, err := db.Get().Exec(`
 		UPDATE dnd_zone_run
 		   SET rooms_cleared = ?,
 		       current_node  = ?,
 		       visited_nodes = ?,
+		       rooms_traversed = rooms_traversed + 1,
 		       last_action_at = CURRENT_TIMESTAMP
 		 WHERE run_id = ?`,
 		string(clearedJSON), nextNode, string(visitedJSON), runID,
@@ -476,6 +538,8 @@ func markRoomCleared(runID string) (RoomType, error) {
 	}
 	r.CurrentNode = nextNode
 	r.VisitedNodes = visited
+	r.RoomsTraversed++
+	r.CurrentRoom = pathIndexOf(visited, nextNode)
 	return nodeKindToRoomType(g.Nodes[nextNode].Kind), nil
 }
 

internal/plugin/zone_graph_nav.go

@@ -315,7 +315,7 @@ func recordRoomCleared(runID string) (*DungeonRun, error) {
 	if !r.IsActive() {
 		return nil, ErrNoActiveRun
 	}
-	cleared := append(r.RoomsCleared, r.CurrentRoom)
+	cleared := appendClearedRoom(r.RoomsCleared, r.CurrentRoom)
 	clearedJSON, _ := json.Marshal(cleared)
 	if _, err := db.Get().Exec(`
 		UPDATE dnd_zone_run
@@ -376,28 +376,36 @@ func completeRunAtNode(runID string, boss bool) error {
 	return err
 }
 
-// advanceZoneRunNode moves a run to nextNode: appends to visited_nodes,
-// sets current_node, and clears any pending fork prompt. Caller is
-// expected to have already called recordRoomCleared for the prior node.
-func advanceZoneRunNode(runID, nextNode string) error {
+// advanceZoneRunNode moves a run to nextNode: records the node entry in
+// visited_nodes, sets current_node, bumps the traversal counter, and clears
+// any pending fork prompt. Caller is expected to have already called
+// recordRoomCleared for the prior node.
+//
+// Returns the moved-to room's path index so callers can label it without
+// assuming CurrentRoom+1 — an assumption that only holds while the player
+// is walking the frontier.
+func advanceZoneRunNode(runID, nextNode string) (int, error) {
 	r, err := getZoneRun(runID)
 	if err != nil {
-		return err
+		return 0, err
 	}
 	if r == nil {
-		return ErrNoActiveRun
+		return 0, ErrNoActiveRun
 	}
-	visited := append(r.VisitedNodes, nextNode)
+	visited := appendVisited(r.VisitedNodes, nextNode)
 	visitedJSON, _ := json.Marshal(visited)
-	_, err = db.Get().Exec(`
+	if _, err := db.Get().Exec(`
 		UPDATE dnd_zone_run
 		   SET current_node  = ?,
 		       visited_nodes = ?,
 		       node_choices  = '{}',
+		       rooms_traversed = rooms_traversed + 1,
 		       last_action_at = CURRENT_TIMESTAMP
 		 WHERE run_id = ?`,
-		nextNode, string(visitedJSON), runID)
-	return err
+		nextNode, string(visitedJSON), runID); err != nil {
+		return 0, err
+	}
+	return pathIndexOf(visited, nextNode), nil
 }
 
 // resolveForkChoice takes a 1-based choice index against a pending

internal/plugin/zone_revisit_r1_test.go

@@ -0,0 +1,257 @@
+package plugin
+
+import (
+	"encoding/json"
+	"testing"
+
+	"gogobee/internal/db"
+	"maunium.net/go/mautrix/id"
+)
+
+// Revisit R1 (gogobee_revisit_plan.md §R1) — the structural split between
+// "where am I on the path" (CurrentRoom) and "how far have I walked"
+// (RoomsTraversed). No player-visible behavior changes in R1; these tests
+// pin the invariants R2's `!revisit` will lean on.
+
+// setupRevisitTestDB builds a schema-only database in a temp dir. Unlike
+// setupZoneRunTestDB it does not copy the operator's data/gogobee.db, so it
+// runs everywhere instead of skipping on any machine that lacks one — these
+// tests assert the R1 invariants, which no prod row is needed to exercise.
+func setupRevisitTestDB(t *testing.T) {
+	t.Helper()
+	db.Close()
+	if err := db.Init(t.TempDir()); err != nil {
+		t.Fatalf("db.Init: %v", err)
+	}
+	t.Cleanup(db.Close)
+}
+
+// ── pure helpers ────────────────────────────────────────────────────────────
+
+func TestPathIndexOf_ReturnsFirstEntryIndex(t *testing.T) {
+	// A backtracked path: the player walked r1→r2→r3, then back to r2.
+	// r2's room number must stay 1 — the number they were shown on the way
+	// in, and the salt every enemy/trap/harvest key downstream hashes.
+	visited := []string{"z.r1", "z.r2", "z.r3"}
+	if got := pathIndexOf(visited, "z.r2"); got != 1 {
+		t.Errorf("pathIndexOf(r2) = %d, want 1", got)
+	}
+	if got := pathIndexOf(visited, "z.r3"); got != 2 {
+		t.Errorf("pathIndexOf(r3) = %d, want 2", got)
+	}
+}
+
+func TestPathIndexOf_FallsBackToTailWhenAbsent(t *testing.T) {
+	// Pre-G4 rows carry a current_node that was never recorded as visited.
+	// The fallback must reproduce the pre-R1 derivation (len-1), not 0 —
+	// pinning such a row to the entry room would re-fire the entry encounter.
+	visited := []string{"z.r1", "z.r2", "z.r3"}
+	if got := pathIndexOf(visited, "z.nowhere"); got != 2 {
+		t.Errorf("pathIndexOf(absent) = %d, want tail index 2", got)
+	}
+	if got := pathIndexOf(nil, "z.r1"); got != 0 {
+		t.Errorf("pathIndexOf(empty) = %d, want 0", got)
+	}
+}
+
+func TestAppendVisited_DoesNotRenumberOnRevisit(t *testing.T) {
+	visited := []string{"z.r1", "z.r2"}
+	again := appendVisited(visited, "z.r1")
+	if len(again) != 2 {
+		t.Fatalf("re-entering a visited node appended: %v", again)
+	}
+	fresh := appendVisited(again, "z.r3")
+	if len(fresh) != 3 || fresh[2] != "z.r3" {
+		t.Errorf("new node not appended in order: %v", fresh)
+	}
+}
+
+func TestAppendClearedRoom_IsIdempotent(t *testing.T) {
+	// Walking out of room 1 twice must not inflate RoomsCleared — its
+	// length feeds "N/M rooms" renders and would eventually exceed TotalRooms.
+	cleared := appendClearedRoom([]int{0, 1}, 1)
+	if len(cleared) != 2 {
+		t.Fatalf("re-clearing room 1 appended: %v", cleared)
+	}
+	if got := appendClearedRoom(cleared, 2); len(got) != 3 {
+		t.Errorf("fresh room not appended: %v", got)
+	}
+}
+
+// ── the load-bearing property: CurrentRoom tracks the node, not the tail ────
+
+func TestCurrentRoom_DerivesFromCurrentNodeNotVisitedTail(t *testing.T) {
+	setupRevisitTestDB(t)
+	uid := id.UserID("@r1-backtrack:example")
+
+	run, err := startZoneRun(uid, ZoneGoblinWarrens, 1, nil)
+	if err != nil {
+		t.Fatalf("startZoneRun: %v", err)
+	}
+	// Walk forward two rooms so VisitedNodes has a tail distinct from
+	// the node we're about to stand on.
+	for i := 0; i < 2; i++ {
+		if _, err := markRoomCleared(run.RunID); err != nil {
+			t.Fatalf("markRoomCleared %d: %v", i, err)
+		}
+	}
+	fwd, err := getZoneRun(run.RunID)
+	if err != nil || fwd == nil {
+		t.Fatalf("reload: %v", err)
+	}
+	if len(fwd.VisitedNodes) != 3 {
+		t.Fatalf("expected 3 visited nodes, got %v", fwd.VisitedNodes)
+	}
+	if fwd.CurrentRoom != 2 {
+		t.Errorf("forward CurrentRoom = %d, want 2", fwd.CurrentRoom)
+	}
+
+	// Simulate the backtrack R2 will perform: current_node moves back to
+	// the first room, visited_nodes is untouched. Pre-R1 this read as
+	// room 2 (the tail); it must now read as room 0.
+	backTo := fwd.VisitedNodes[0]
+	if _, err := db.Get().Exec(
+		`UPDATE dnd_zone_run SET current_node = ? WHERE run_id = ?`,
+		backTo, run.RunID); err != nil {
+		t.Fatalf("backtrack write: %v", err)
+	}
+	back, err := getZoneRun(run.RunID)
+	if err != nil || back == nil {
+		t.Fatalf("reload after backtrack: %v", err)
+	}
+	if back.CurrentRoom != 0 {
+		t.Errorf("after backtrack CurrentRoom = %d, want 0 (the node's first-entry index)", back.CurrentRoom)
+	}
+	if len(back.VisitedNodes) != 3 {
+		t.Errorf("backtrack must not shrink VisitedNodes: %v", back.VisitedNodes)
+	}
+	// The step counter does not rewind with the player.
+	if back.RoomsTraversed != 3 {
+		t.Errorf("RoomsTraversed = %d, want 3 (monotonic)", back.RoomsTraversed)
+	}
+}
+
+// ── R1's stated acceptance: forward-only trajectories are unchanged ─────────
+
+func TestForwardOnlyRun_KeepsTraversalLockedToPathIndex(t *testing.T) {
+	setupRevisitTestDB(t)
+	uid := id.UserID("@r1-forward:example")
+
+	run, err := startZoneRun(uid, ZoneGoblinWarrens, 1, nil)
+	if err != nil {
+		t.Fatalf("startZoneRun: %v", err)
+	}
+	if run.RoomsTraversed != 1 {
+		t.Fatalf("fresh run RoomsTraversed = %d, want 1 (entry room walked into)", run.RoomsTraversed)
+	}
+
+	for step := 0; step < 3; step++ {
+		if _, err := markRoomCleared(run.RunID); err != nil {
+			t.Fatalf("markRoomCleared %d: %v", step, err)
+		}
+		cur, err := getZoneRun(run.RunID)
+		if err != nil || cur == nil {
+			t.Fatalf("reload %d: %v", step, err)
+		}
+		// This is the identity every pre-R1 caller silently assumed. As long
+		// as navigation is forward-only it must keep holding, or R1 has
+		// changed behavior it promised not to.
+		if cur.RoomsTraversed != cur.CurrentRoom+1 {
+			t.Errorf("step %d: RoomsTraversed=%d, CurrentRoom=%d — want traversed == room+1",
+				step, cur.RoomsTraversed, cur.CurrentRoom)
+		}
+		if cur.RoomsTraversed != len(cur.VisitedNodes) {
+			t.Errorf("step %d: RoomsTraversed=%d, len(VisitedNodes)=%d — want equal on a forward-only run",
+				step, cur.RoomsTraversed, len(cur.VisitedNodes))
+		}
+		// narrationCadence is the pre-R1 salt: len(VisitedNodes)-1. Any drift
+		// here silently re-keys every flavor pool for in-flight runs.
+		if got, want := narrationCadence(cur), len(cur.VisitedNodes)-1; got != want {
+			t.Errorf("step %d: narrationCadence = %d, want %d (pre-R1 salt)", step, got, want)
+		}
+	}
+}
+
+func TestNarrationCadence_TracksTraversalNotPosition(t *testing.T) {
+	// A backtracked run: standing in room 0, but three rooms walked. Flavor
+	// should keep advancing, so a player who doubles back reads new lines
+	// instead of the entry-room narration a second time.
+	run := &DungeonRun{
+		VisitedNodes:   []string{"z.r1", "z.r2", "z.r3"},
+		CurrentNode:    "z.r1",
+		CurrentRoom:    0,
+		RoomsTraversed: 4,
+	}
+	if got := narrationCadence(run); got != 3 {
+		t.Errorf("narrationCadence = %d, want 3 (traversals-1), not the room index", got)
+	}
+	// Rows not yet swept by the bootstrap fall back to the visited count.
+	stale := &DungeonRun{VisitedNodes: []string{"z.r1", "z.r2"}}
+	if got := narrationCadence(stale); got != 1 {
+		t.Errorf("un-backfilled row cadence = %d, want 1", got)
+	}
+}
+
+// ── bootstrap ───────────────────────────────────────────────────────────────
+
+func TestBootstrapRoomsTraversed_BackfillsFromVisitedNodes(t *testing.T) {
+	setupRevisitTestDB(t)
+	uid := id.UserID("@r1-bootstrap:example")
+
+	run, err := startZoneRun(uid, ZoneGoblinWarrens, 1, nil)
+	if err != nil {
+		t.Fatalf("startZoneRun: %v", err)
+	}
+	visited := []string{"gw.r1", "gw.r2", "gw.r3", "gw.r4"}
+	visitedJSON, _ := json.Marshal(visited)
+	// Reproduce a row as the ALTER leaves it: a real path, counter at 0.
+	if _, err := db.Get().Exec(
+		`UPDATE dnd_zone_run SET visited_nodes = ?, rooms_traversed = 0 WHERE run_id = ?`,
+		string(visitedJSON), run.RunID); err != nil {
+		t.Fatalf("seed pre-R1 row: %v", err)
+	}
+
+	bootstrapRoomsTraversed()
+
+	got, err := getZoneRun(run.RunID)
+	if err != nil || got == nil {
+		t.Fatalf("reload: %v", err)
+	}
+	if got.RoomsTraversed != 4 {
+		t.Errorf("RoomsTraversed = %d, want 4 (len(visited_nodes))", got.RoomsTraversed)
+	}
+
+	// Idempotent: a second sweep must not touch the row it already fixed,
+	// nor the counter of a run that has since walked on.
+	if _, err := db.Get().Exec(
+		`UPDATE dnd_zone_run SET rooms_traversed = 9 WHERE run_id = ?`, run.RunID); err != nil {
+		t.Fatalf("bump: %v", err)
+	}
+	bootstrapRoomsTraversed()
+	again, _ := getZoneRun(run.RunID)
+	if again.RoomsTraversed != 9 {
+		t.Errorf("re-run clobbered a live counter: got %d, want 9", again.RoomsTraversed)
+	}
+}
+
+// An empty visited_nodes must not backfill to 0 and re-arm the sentinel —
+// the row would be swept on every single boot.
+func TestBootstrapRoomsTraversed_FloorsAtOne(t *testing.T) {
+	setupRevisitTestDB(t)
+	uid := id.UserID("@r1-empty-path:example")
+
+	run, err := startZoneRun(uid, ZoneGoblinWarrens, 1, nil)
+	if err != nil {
+		t.Fatalf("startZoneRun: %v", err)
+	}
+	if _, err := db.Get().Exec(
+		`UPDATE dnd_zone_run SET visited_nodes = '[]', rooms_traversed = 0 WHERE run_id = ?`,
+		run.RunID); err != nil {
+		t.Fatalf("seed: %v", err)
+	}
+	bootstrapRoomsTraversed()
+	got, _ := getZoneRun(run.RunID)
+	if got.RoomsTraversed != 1 {
+		t.Errorf("RoomsTraversed = %d, want 1 (floor)", got.RoomsTraversed)
+	}
+}