refactor: add JSDoc to aws.getState() clarifying test-only usage (#2651)

this function has no callers in production code but is intentionally
used in unit tests (custom-flag.test.ts) for state introspection.
adding documentation prevents it from being incorrectly identified
as dead code in future code quality scans.

code quality scan results:
- dead code: none found
- stale references: none found
- python usage: none found
- duplicate utilities: getCloudInitUserdata has per-cloud variants
  with intentional differences (not mergeable)
- stale comments: none found

-- qa/code-quality

Co-authored-by: spawn-qa-bot <qa@openrouter.ai>

packages/cli/src/aws/aws.ts

@@ -194,6 +194,7 @@ const _state: AwsState = {
   keyPairName: "spawn-key",
 };
 
+/** Introspect internal state (used by tests). */
 export function getState() {
   return {
     awsRegion: _state.region,