feat: robustness in Module 5 (nesting guard, Death Phase limit, well-formed Assemble, multi-summon order)

A trigger is never queued while that same (minion, trigger) is resolving;
more than DEATH_PHASE_LIMIT = 64 Death Phases is an error ('Death Phase
limit'); Assemble refuses and never offers ill-formed text (wellFormed /
well_formed); summon count > 1 places tokens in summon order. Modules 05-10,
both tracks. Four new Module 5 tests, a tools test that every shipped card
is well-formed, lessons 2, 3, 5, 13 and harness.md updated.

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

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

@@ -143,6 +143,28 @@ export function compile(def: CardDef, inPool: boolean): Card {
 
 export const hasTrigger = (card: Card, on: TriggerOn): boolean => card.triggers.some((t) => t.on === on);
 
+/**
+ * Does `text` mean what it says? For a minion, every effect clause belongs to a
+ * trigger (none comes before the first trigger, or after an aura or keyword), and
+ * every trigger has at least one effect before the next trigger, aura, keyword or
+ * the end. The rule is for minions (Assemble makes only minions): a spell passes.
+ */
+export function wellFormed(text: readonly Clause[], type: CardDef["type"]): boolean {
+  if (type !== "minion") return true;
+  // The trigger whose effects are being listed: none, one with no effect yet, or one with some.
+  let open: "none" | "empty" | "filled" = "none";
+  for (const clause of text) {
+    if (clause.kind === "effect") {
+      if (open === "none") return false;
+      open = "filled";
+    } else {
+      if (open === "empty") return false;
+      open = clause.kind === "trigger" ? "empty" : "none";
+    }
+  }
+  return open !== "empty";
+}
+
 /** Every card the game can create, looked up by name. */
 export class CardLibrary {
   private readonly cards = new Map<string, Card>();