feat(gameplay): enforce core SRD d20 rules

Co-authored-by: multica-agent <github@multica.ai>

apps/worker/src/orchestration.ts

@@ -64,6 +64,13 @@ export function validateAndOrderRoundPlan(planInput: unknown, context: RoundCont
   for (const check of plan.checks) {
     if (!characterIds.has(check.actorId)) throw new Error(`Unknown check actor ${check.actorId}`)
     if (check.targetId && !characterIds.has(check.targetId)) throw new Error(`Unknown check target ${check.targetId}`)
+    if (check.kind === 'skill' && !check.skill) throw new Error('Skill checks require a skill')
+    if (['ability', 'savingThrow'].includes(check.kind) && !check.ability) throw new Error(`${check.kind} checks require an ability`)
+    if (['ability', 'skill', 'savingThrow'].includes(check.kind) && check.difficulty === undefined) {
+      throw new Error(`${check.kind} checks require a Difficulty Class`)
+    }
+    if (check.kind === 'attack' && !check.targetId) throw new Error('Attack rolls require a target')
+    if (['damage', 'healing'].includes(check.kind) && !check.targetId) throw new Error(`${check.kind} rolls require a target`)
   }
   for (const event of plan.proposedEvents) {
     if (event.actorId && !characterIds.has(event.actorId)) throw new Error(`Unknown event actor ${event.actorId}`)