Review follow-ups: harden the extraction guard, fix Misty/concentration ordering

Applying /code-review high findings on the review-follow-up stack:

- expeditionCmdStart: the resumable-extraction guard swallowed a partySize
  error and fell open, starting a new expedition on top of a still-seated
  party — the exact orphaning it exists to prevent. Now checks
  extractionLapsed first (no DB call on the reap path) and treats a
  roster-read error as "assume occupied → refuse".
- Lapsed reap on !expedition start silently unseated members. Extracted a
  shared reapLapsedExtraction helper (reap + notify the roster) and routed
  both the hourly sweeper and the start-path reap through it.
- stepRoundEnd: moved Misty's crowd/heal seat-loop after the concentration
  tick so a caster whose lingering aura would kill the enemy that round wins
  before the end-of-round crowd swing, honoring the concentration block's
  "a lethal pulse settles the fight" intent.
- Promoted the misty_heal event-log scan to a shared hasAction helper.
- Renamed the new sweep test off the dnd_ prefix.

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

internal/plugin/combat_session_build.go

@@ -225,13 +225,6 @@ func seatCombatResult(sess *CombatSession, seat int) CombatResult {
 	hp, hpMax := sess.seatHP(seat), sess.seatHPMax(seat)
 	won := sess.Status == CombatStatusWon
 	events := eventsForSeat(sess.TurnLog, seat)
-	misty := false
-	for _, ev := range events {
-		if ev.Action == "misty_heal" {
-			misty = true
-			break
-		}
-	}
 	return CombatResult{
 		PlayerWon:   won,
 		Events:      events,
@@ -239,10 +232,22 @@ func seatCombatResult(sess *CombatSession, seat int) CombatResult {
 		EnemyEndHP:  sess.EnemyHP,
 		TotalRounds: sess.Round,
 		NearDeath:   won && hp > 0 && float64(hp) < float64(max(1, hpMax))*0.15,
-		MistyHealed: misty,
+		MistyHealed: hasAction(events, "misty_heal"),
 	}
 }
 
+// hasAction reports whether the event log holds at least one event with the
+// given Action. The one-line "did this happen in the fight?" scan the close-out
+// uses to read a proc's outcome off the log rather than a flag.
+func hasAction(events []CombatEvent, action string) bool {
+	for _, e := range events {
+		if e.Action == action {
+			return true
+		}
+	}
+	return false
+}
+
 // postCombatBookkeepingForSeat is postCombatBookkeeping for one seat of a
 // terminal turn-based session — the bridge between what the turn engine
 // persisted and what the shared close-out expects.