fix: final review (engine errors end a Sequence cleanly; nesting guard labelled as the course's; Node 22.15; minor lesson and tool fixes)

I1: run-scenario and both SpellGrid CLIs check moves first and treat any other engine
error as fatal (same text in both tracks); trigger blocks close on error (try/finally,
catch_unwind in Rust); unknown summons rejected. I2, I3, M1-M7, T3, T9a-c, T10a-b.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

course/06-parser/reference/ts/src/engine/queue.ts

@@ -142,7 +142,8 @@ export function summon(world: World, card: string, player: PlayerId, at?: number
 function perform(world: World, action: Action): void {
   switch (action.type) {
     case "damage": {
-      // Area damage: every Damage Event is created, in order of play, before any reaction.
+      // Area damage: every Damage Event is created, in order of play of the intended targets
+      // (a redirected Damage keeps its target's place), before any reaction.
       const targets = [...action.targets].sort((a, b) => world.orderOfPlay(a)! - world.orderOfPlay(b)!);
       const events: Event[] = [];
       for (const target of targets) events.push(applyDamage(world, target, action.amount));
@@ -252,10 +253,14 @@ function react(world: World, events: Event[]): void {
         event.type === "Destroyed" && event.id === source
           ? positionLeftOf(world, world.ownerOf(source), event.before)
           : world.boardIndex(source);
-      // The trigger's consequences are one level deeper in the log tree.
+      // The trigger's consequences are one level deeper in the log tree. The block
+      // closes even if an effect throws, so an error leaves no trigger resolving.
       world.openBlock(source, index);
-      runEffects(world, trigger.effects, new Ctx(world, world.ownerOf(source), source, undefined, position));
-      world.closeBlock();
+      try {
+        runEffects(world, trigger.effects, new Ctx(world, world.ownerOf(source), source, undefined, position));
+      } finally {
+        world.closeBlock();
+      }
     }
   }
 }