Adv 2.0 D&D Phase R7: post-completion audit hardening

High-priority fixes from the multi-agent audit of Adventure 2.0:

- Phase 11 nil-deref cluster: zoneOrFallback() helper replaces 8 unsafe
  getZone(_) sites in dnd_zone_cmd.go. Corrupted zone IDs render a
  placeholder instead of panicking.
- Briefing/recap idempotency: deliverBriefing/deliverRecap now claim
  the rollover via a conditional UPDATE. Double-fires from clock skew
  or restart become no-ops; supply burn and day++ no longer reapply.
- Graceful ticker shutdown: AdventurePlugin gains stopCh + Stop(); all
  11 background tickers now select on stopCh in addition to ticker.C.
- Mood decay (§3.2): math.Round(elapsed*2) replaces int() truncation
  so sub-hour gaps decay correctly.
- 24h auto-abandon (§4.3): getActiveZoneRun returns clean slate and
  abandons stale runs whose LastActionAt is over 24h old.
- Respec / auto-migrate orphan cleanup: !respec and the auto-migrated
  draft wipe now abandon active zone runs and expeditions before
  deleting the dnd_character row.
- Phase R combat-link: applyBossDefeatThreat now wired from
  resolveBossRoom (-20 threat); applyRoomCombatThreatForUser adds
  +5/+8 from non-boss/elite kills (§8.1).
- Starvation → forced extraction: briefing-time check forces extract
  with §10.2 coin tax when supplies hit zero.
- GMNat20/Nat1 narration wired into resolveCombatRoom and
  resolveBossRoom (nat-20 takes precedence over nat-1).
- Treasure-undo race: LoadAndDelete on both timer-fire and `undo`
  paths so only one side wins.
- Battle Master: Disarming, Menacing, Parry maneuvers added (3 → 6
  of 10). Remaining 4 (Pushing, Goading, Riposte, Commander's Strike)
  documented inline as needing ally/reaction mechanics the engine
  doesn't model.
- Threat-70 warning: tracked in RegionState["siege_warning_fired"]
  so a drop-and-recross doesn't re-fire the beat.
- region_state JSON decode error now logged via slog.Warn instead
  of silently discarded.

Failing TestProdDB_DnDLayer fixed via option (a): track migrated
characters and only run round-trip / idempotency assertions on those,
skipping pre-existing prod-DB rows accumulated from live bot use.

New tests in dnd_audit_phase_R7_test.go cover: 24h auto-abandon,
briefing double-fire idempotency, threat-70 warning idempotency,
multi-region extract→resume state preservation, and starvation
forced-extraction.

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

internal/plugin/dnd_zone_run.go

@@ -202,7 +202,15 @@ func startZoneRun(userID id.UserID, zoneID ZoneID, dndLevel int, rng *rand.Rand)
 	return run, nil
 }
 
-// getActiveZoneRun returns the player's in-flight run, or (nil, nil) if none.
+// zoneRunInactivityTimeout is the §4.3 stale-run threshold: a run that
+// has gone untouched for this long is auto-abandoned the next time
+// anyone looks at it.
+const zoneRunInactivityTimeout = 24 * time.Hour
+
+// getActiveZoneRun returns the player's in-flight run, or (nil, nil) if
+// none. If the most-recent active run has been idle longer than
+// zoneRunInactivityTimeout, it's auto-abandoned (§4.3) and the
+// function returns (nil, nil) — the caller sees a clean slate.
 func getActiveZoneRun(userID id.UserID) (*DungeonRun, error) {
 	row := db.Get().QueryRow(`
 		SELECT run_id, user_id, zone_id, current_room, total_rooms,
@@ -220,7 +228,14 @@ func getActiveZoneRun(userID id.UserID) (*DungeonRun, error) {
 	if errors.Is(err, sql.ErrNoRows) {
 		return nil, nil
 	}
-	return r, err
+	if err != nil {
+		return nil, err
+	}
+	if time.Since(r.LastActionAt) > zoneRunInactivityTimeout {
+		_ = abandonZoneRunByID(r.RunID)
+		return nil, nil
+	}
+	return r, nil
 }
 
 // getZoneRun fetches by RunID regardless of completion state. Test/admin use.