post3/todos/POST3-005-xml-responses-extractors.md

POST3-005: XML response builders and extractors

Status: Done Priority: P1 Blocked by: POST3-004

Description

Implement S3-compatible XML response serialization and request query parameter extraction.

Acceptance Criteria

• s3/responses.rs:
  • list_buckets_xml(buckets) — ListAllMyBucketsResult with Owner
  • list_objects_v2_xml(bucket, result, max_keys) — ListBucketResult with Contents
  • error_xml(code, message, resource) — S3 Error response
• s3/extractors.rs:
  • ListObjectsQuery — list-type, prefix, max-keys, continuation-token, start-after, delimiter
• XML output matches S3 format (xmlns, element names, date format ISO 8601)
• All responses include x-amz-request-id header (UUID)