Review follow-up K: a fourth event anchor for the grind loop

The three A6 presence anchors (expedition Night digest, !sell, arena
cashout) miss a whole playstyle: a player who only mines/forages/fishes
(now automatic, done by walking) and clears single-day dungeons, but
never sells, never enters the arena, and never runs a multi-day
expedition to a Night camp, would roll for zero mid-day events.

Anchor a fourth roll on a foreground single-day zone clear — the climax
DM that player is reading, and one they cannot spam (a clear costs a
full walk). advanceResult.zoneCleared is set only in the full-clear
branch (a mid-zone region clear continues the run and would fire per
region), and the roll lives in zoneCmdAdvance, the foreground path only:
autopilot goes through runAutopilotWalk and party members are refused
earlier by isPartyMember. The per-day slot guard still caps everyone at
one event/day, so the three prior anchors are unmoved.

advEventChanceZoneClear = 0.08 puts a zone-clear-only player at ~1
event/week, matching the fully-engaged player; it is the tuning knob.

Claude-Session: https://claude.ai/code/session_017mEwUmmS7aQTP2NQXj6rUa

internal/plugin/adventure_events.go

@@ -32,10 +32,23 @@ type advActiveEvent struct {
 //
 // The per-anchor chances below put a player who hits all three at ~1 event
 // per week; see TestAnchoredEventWeeklyRate.
+//
+// K — the three social/economic anchors miss the pure grind loop: a player who
+// only mines/forages/fishes (now automatic, done by walking) and clears
+// single-day dungeons, but never sells, never enters the arena, and never runs
+// a multi-day expedition to a Night camp, would roll for zero events. The
+// fourth anchor, ZoneClear, fires on a foreground single-day zone clear — the
+// climax DM that player *is* reading — so they get the same rough cadence.
+// Autopilot walks and mid-zone region clears deliberately do not fire it (see
+// zoneCmdAdvance / the full-clear branch of advanceOnceWithOpts). The per-day
+// slot still caps everyone at one event, so a player who happens to hit two
+// anchors in a day can't double up. This rate is the tuning knob for item K —
+// bump it if telemetry shows the grind-loop player still sees too few.
 const (
-	advEventChanceDigest = 0.08
-	advEventChanceSell   = 0.05
-	advEventChanceArena  = 0.05
+	advEventChanceDigest    = 0.08
+	advEventChanceSell      = 0.05
+	advEventChanceArena     = 0.05
+	advEventChanceZoneClear = 0.08
 )
 
 var (

internal/plugin/adventure_events_test.go

@@ -44,6 +44,43 @@ func TestAnchoredEventWeeklyRate(t *testing.T) {
 	}
 }
 
+// TestZoneClearAnchorRate pins item K's fourth anchor for the population the
+// other three miss: a grind-loop player who never sells, never enters the
+// arena, and never runs a multi-day expedition, but clears single-day zones.
+// Modelled at two foreground clears per active day (a plausible dungeon
+// session) they should land in the same ~1 event/week band as the fully-
+// engaged player — that is the whole point of adding the anchor. The clears/day
+// assumption and advEventChanceZoneClear are the two tuning knobs; see the K
+// note in adventure_events.go.
+func TestZoneClearAnchorRate(t *testing.T) {
+	const clearsPerDay = 2
+
+	const weeks = 20000
+	rng := rand.New(rand.NewPCG(0x5EED, 0x2C)) // "ZC"
+	events := 0
+	for range weeks {
+		for range 7 {
+			firedToday := false
+			for range clearsPerDay {
+				if firedToday {
+					break // one event per player per UTC day
+				}
+				if rng.Float64() < advEventChanceZoneClear {
+					firedToday = true
+				}
+			}
+			if firedToday {
+				events++
+			}
+		}
+	}
+
+	perWeek := float64(events) / weeks
+	if perWeek < 0.8 || perWeek > 1.5 {
+		t.Errorf("zone-clear anchor = %.3f/week, want ~1 (0.8–1.5)", perWeek)
+	}
+}
+
 // TestClaimDailyEventSlot_OnePerDay guards the cap the rate test assumes.
 func TestClaimDailyEventSlot_OnePerDay(t *testing.T) {
 	uid := id.UserID("@events-slot:example")

internal/plugin/dnd_zone_cmd.go

@@ -471,6 +471,12 @@ type advanceResult struct {
 	// harvest ran (Entry/Trap/Elite/Boss rooms, forks, stops).
 	harvest       autoHarvestResult
 	harvestFooter string
+	// zoneCleared is true only when this step was a *full* zone clear
+	// (reason == stopComplete and not a mid-zone region clear). The K
+	// event anchor reads it so a foreground `!zone advance` clear can roll
+	// the grind-loop player's mid-day event — a mid-zone region clear does
+	// not, since the run continues and it would fire per region.
+	zoneCleared bool
 }
 
 // zoneCmdAdvance resolves the room the player is currently standing in,
@@ -495,7 +501,16 @@ func (p *AdventurePlugin) zoneCmdAdvance(ctx MessageContext) error {
 	if err != nil {
 		return p.SendDM(ctx.Sender, err.Error())
 	}
-	return p.streamOrSend(ctx.Sender, res.preStream, res.intro, res.phases, res.final)
+	sendErr := p.streamOrSend(ctx.Sender, res.preStream, res.intro, res.phases, res.final)
+	// K fourth event anchor: a foreground single-day zone clear is a presence
+	// moment for the grind-loop player the other three anchors miss. Rolled
+	// after the clear DM so any triggered event lands behind it, and only here
+	// — zoneCmdAdvance is the foreground path; autopilot walks go through
+	// runAutopilotWalk and never reach this.
+	if res.zoneCleared {
+		p.maybeFireAnchoredEvent(ctx.Sender, advEventChanceZoneClear)
+	}
+	return sendErr
 }
 
 // advanceOnce runs the single-room advance pipeline and returns a
@@ -737,7 +752,8 @@ func (p *AdventurePlugin) advanceOnceWithOpts(ctx MessageContext, compact, inlin
 		// and point at the next one — "Cleared {zone}. Run complete." reads
 		// wrong right before the auto-advance transit block (and is shared with
 		// manual `!region travel`, which advances next).
-		if region, next, midZone := midZoneRegionClear(ctx.Sender, run.RunID); midZone {
+		region, next, midZone := midZoneRegionClear(ctx.Sender, run.RunID)
+		if midZone {
 			b.WriteString(fmt.Sprintf("🏁 **Cleared %s.** The way to %s opens ahead.\n\n", region.Name, next.Name))
 		} else {
 			b.WriteString(fmt.Sprintf("🏆 **Cleared %s.** Run complete.\n\n", zone.Display))
@@ -763,11 +779,12 @@ func (p *AdventurePlugin) advanceOnceWithOpts(ctx MessageContext, compact, inlin
 			}
 		}
 		return advanceResult{
-			preStream: preStream,
-			intro:     intro,
-			phases:    phases,
-			final:     b.String(),
-			reason:    stopComplete,
+			preStream:   preStream,
+			intro:       intro,
+			phases:      phases,
+			final:       b.String(),
+			reason:      stopComplete,
+			zoneCleared: !midZone,
 		}, nil
 	}
 	if forkMsg != "" {