fix: wrap do-while loop body in try/catch to protect against exceptions

Any exception from createReactionMessage or renderTemplate inside the
defense/attack reaction loops would silently abort the handler, preventing
combat result creation. The try/catch logs the error and continues safely.

module/hooks/chat-reaction.mjs

@@ -466,6 +466,7 @@ Hooks.on("createChatMessage", async (message) => {
   let d30AttackPrecomputedStale = false
 
   do {
+    try {
     mulliganRestart = false
     defenderHandledBonus = false
     attackerHandledBonus = false
@@ -829,6 +830,10 @@ Hooks.on("createChatMessage", async (message) => {
         mulliganRestart = true
       }
     }
+  } catch(e) {
+    console.error("Defense handler loop error (non-fatal):", e)
+    mulliganRestart = false
+  }
   } while (mulliganRestart)
 
   const shieldDamageReduction = shieldBlocked ? shieldReaction?.damageReduction ?? 0 : 0