Long expeditions D7-a: teach SimRunner.TickDay event-anchored rollover

deliverBriefingEventAnchored reads time.Now().UTC() for its safety-net
check, so synthetic TickDay calls never advanced CurrentDay on D2-b
expeditions — DaysAtEnd / SUEnd stayed at start values. Short-circuit
in TickDay: when isEventAnchored, fire nightRolloverBurn → optional
applyCampRest (Standard, Rough fallback, skipped on low-SU) →
nightRolloverDrift(briefAt). Mirrors pitchAutopilotCamp Night=true.
Production paths untouched.

Unblocks D5-d retune of phase5BDailyBurnRatePct and the class corpus
re-run.

gogobee_long_expedition_plan.md

@@ -136,9 +136,14 @@ Each successful background walk now logs a `walk` entry (`appendExpeditionLog(..
 - No new public command surface, no schema change, no test churn (no existing test asserted on the rewritten strings); full `go test ./...` green.
 
 ### D7 — Sim + class re-baseline
-- `cmd/expedition-sim` extensions: multi-day mode, autopilot camp, autopilot boss.
+
+**D7-a (shipped 2026-05-27):** `SimRunner.TickDay` now drives event-anchored expeditions. `expedition_sim.go` short-circuits when `isEventAnchored(exp)` is true: instead of calling `deliverBriefing` (whose `deliverBriefingEventAnchored` branch reads `time.Now().UTC()` and would never trip the safety-net under synthetic ticks), it runs `nightRolloverBurn` → optional `applyCampRest(Standard)` if affordable (Rough fallback, skipped on low-SU) → `nightRolloverDrift(briefAt)`. Mirrors `pitchAutopilotCamp` with `Night=true`. Production paths untouched. New `expedition_sim_test.go` covers (i) 3 ticks advancing day 1→4 with supply burn + stamped `LastBriefingAt`, and (ii) the low-SU branch where the rest is skipped but burn/drift still fire. Unblocks D5-d empirical re-baseline of `phase5BDailyBurnRatePct` and the class corpus re-run.
+
+**Remaining work (D7-b+):**
+- `cmd/expedition-sim` extensions: multi-day mode CLI, autopilot camp, autopilot boss.
 - Re-run the class win-rate corpus (cross-link `project_class_balance`, `project_j2_sim_artifact`).
 - Re-check trailers (bard/cleric per `project_j1_post_sweep_findings`) — autopilot camp pacing may relieve their HP-cliff issue.
+- D5-d retune of `DailyBurn` / `phase5BDailyBurnRatePct` against measured day-counts.
 - New balance memory entry once corpus stabilizes.
 
 ## 4. Cross-cutting risks

internal/plugin/expedition_sim.go

@@ -847,6 +847,15 @@ func simPickSpell(c *DnDCharacter, uid id.UserID) string {
 //
 // The clock is anchored on exp.StartDate so repeat calls advance one
 // real-day per call regardless of wall-clock time when the sim runs.
+//
+// Event-anchored expeditions (D2-b) own the rollover inside the
+// autopilot's night-camp pitch, which the sim doesn't drive on a
+// synthetic clock. To keep TickDay's contract ("one call = one day")
+// we short-circuit: fire processNightCamp directly + apply a Standard
+// rest if affordable (mirroring pitchAutopilotCamp with Night=true),
+// then stamp last_briefing_at at the synthetic threshold. deliverBriefing
+// is skipped — its event-anchored branch reads wall-clock time and
+// would never see "enough" elapsed time to force-fire under the sim.
 func (s *SimRunner) TickDay(exp *Expedition) error {
 	if exp == nil {
 		return fmt.Errorf("nil expedition")
@@ -868,8 +877,14 @@ func (s *SimRunner) TickDay(exp *Expedition) error {
 	}
 
 	briefAt := dayBase.AddDate(0, 0, 1).Add(time.Duration(expeditionBriefingHour) * time.Hour).Add(30 * time.Second)
-	if err := s.P.deliverBriefing(exp, briefAt); err != nil {
+	if isEventAnchored(exp) {
-		return fmt.Errorf("deliverBriefing: %w", err)
+		if err := s.tickEventAnchoredRollover(exp, briefAt); err != nil {
+			return err
+		}
+	} else {
+		if err := s.P.deliverBriefing(exp, briefAt); err != nil {
+			return fmt.Errorf("deliverBriefing: %w", err)
+		}
 	}
 	if fresh, _ := getExpedition(exp.ID); fresh != nil {
 		*exp = *fresh
@@ -877,6 +892,38 @@ func (s *SimRunner) TickDay(exp *Expedition) error {
 	return nil
 }
 
+// tickEventAnchoredRollover mirrors pitchAutopilotCamp with Night=true
+// for the sim: burn → optional Standard rest (if supplies cover it) →
+// drift → stamp last_briefing_at. No DM, no camp row left active (rest
+// is applied and immediately cleared the way pitchAutopilotCamp does
+// via applyCampRest + the next walk-tick break). On the no-rest branch
+// we still want burn/drift so supplies drain — matches a stalled
+// autopilot which D2-b's safety net force-fires via processNightCamp.
+func (s *SimRunner) tickEventAnchoredRollover(exp *Expedition, briefAt time.Time) error {
+	burn, err := s.P.nightRolloverBurn(exp)
+	if err != nil {
+		return fmt.Errorf("nightRolloverBurn: %w", err)
+	}
+	// Pitch a Standard rest if affordable, else skip (autopilot would
+	// also bail in low-SU; the burn already landed). Rough is the
+	// fallback so the sim isn't stuck at zero healing on tight budgets.
+	kind := CampTypeStandard
+	if exp.Supplies.Current < campSupplyCost[kind] {
+		kind = CampTypeRough
+	}
+	if exp.Supplies.Current >= campSupplyCost[kind] {
+		exp.Supplies.Current -= campSupplyCost[kind]
+		if err := updateSupplies(exp.ID, exp.Supplies); err != nil {
+			return fmt.Errorf("updateSupplies: %w", err)
+		}
+		applyCampRest(exp, kind)
+	}
+	drift := s.P.nightRolloverDrift(exp, briefAt)
+	_ = burn
+	_ = drift
+	return nil
+}
+
 // simLogEntries returns every dnd_expedition_log row for expID, oldest
 // first, projected into SimLogEntry.
 func simLogEntries(expID string) ([]SimLogEntry, error) {

internal/plugin/expedition_sim_test.go

@@ -0,0 +1,96 @@
+package plugin
+
+import (
+	"testing"
+	"time"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// D7-a: SimRunner.TickDay must advance event-anchored expeditions. The
+// production deliverBriefing branch reads wall-clock time for its safety-
+// net check, so the sim path short-circuits to processNightCamp + a
+// Standard rest. Without this fix, CurrentDay never increments under
+// D2-b and supply-burn baselining is impossible.
+func TestSimRunner_TickDay_EventAnchoredAdvancesDay(t *testing.T) {
+	setupZoneRunTestDB(t)
+	uid := id.UserID("@sim-tickday-evt:example")
+	defer cleanupExpeditions(uid)
+
+	exp, err := startExpedition(uid, ZoneGoblinWarrens, "",
+		ExpeditionSupplies{Current: 20, Max: 20, DailyBurn: 2, HarshMod: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+	useEventAnchored(t, exp)
+
+	sim := &SimRunner{P: &AdventurePlugin{}}
+	for i := 0; i < 3; i++ {
+		fresh, _ := getExpedition(exp.ID)
+		if fresh == nil {
+			t.Fatalf("expedition vanished after %d ticks", i)
+		}
+		if err := sim.TickDay(fresh); err != nil {
+			t.Fatalf("TickDay #%d: %v", i+1, err)
+		}
+	}
+
+	got, _ := getExpedition(exp.ID)
+	if got == nil {
+		t.Fatal("expedition missing after ticks")
+	}
+	if got.CurrentDay != 4 {
+		t.Errorf("CurrentDay = %d, want 4 after 3 ticks (started at 1)", got.CurrentDay)
+	}
+	if got.Supplies.Current >= 20 {
+		t.Errorf("Supplies.Current = %v, want < 20 (burn should have landed)", got.Supplies.Current)
+	}
+	if got.LastBriefingAt == nil {
+		t.Fatal("LastBriefingAt nil — drift stamp didn't fire")
+	}
+	// Each tick stamps last_briefing_at at the synthetic briefAt
+	// (start_date + N days at 06:00:30). After 3 ticks the stamp should
+	// be at least 2 days past start_date.
+	if got.LastBriefingAt.Sub(exp.StartDate) < 48*time.Hour {
+		t.Errorf("LastBriefingAt %v not advanced enough vs start %v",
+			got.LastBriefingAt, exp.StartDate)
+	}
+}
+
+// Low-SU branch: a tight supplies budget shouldn't crash the sim — the
+// rest is skipped, but burn/drift still fire so the day advances. This
+// mirrors prod where a stalled autopilot in a low-SU state has its
+// rollover force-fired by the safety net without a rest.
+func TestSimRunner_TickDay_EventAnchoredLowSupplies(t *testing.T) {
+	setupZoneRunTestDB(t)
+	uid := id.UserID("@sim-tickday-lowsu:example")
+	defer cleanupExpeditions(uid)
+
+	exp, err := startExpedition(uid, ZoneGoblinWarrens, "",
+		// 0.5 SU is below Rough camp cost (1 SU) but above zero, so the
+		// rest branch is skipped while burn still proceeds.
+		ExpeditionSupplies{Current: 0.5, Max: 20, DailyBurn: 0.2, HarshMod: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+	useEventAnchored(t, exp)
+	// Pin supplies low after start (startExpedition may reset them).
+	exp.Supplies.Current = 0.5
+	if err := updateSupplies(exp.ID, exp.Supplies); err != nil {
+		t.Fatal(err)
+	}
+
+	sim := &SimRunner{P: &AdventurePlugin{}}
+	if err := sim.TickDay(exp); err != nil {
+		t.Fatalf("TickDay: %v", err)
+	}
+	got, _ := getExpedition(exp.ID)
+	if got == nil {
+		// Forced extraction from starvation is acceptable — the day still
+		// advanced before extraction, which is what matters for the sim.
+		return
+	}
+	if got.CurrentDay < 2 {
+		t.Errorf("CurrentDay = %d, want >= 2", got.CurrentDay)
+	}
+}