Reduce workflow boilerplate with native if/else branching

Breaking change: website crawling uses per-page content hashes

We changed the WebsiteReader deduplication model to compute content hashes per page. This aligns skip_if_exists with page-level updates and ensures accurate re-crawls.

Consistent async file reads: empty files now return no documents

Async text_reader.aread() now returns an empty list ([]) for empty files, aligning behavior with the sync API. This removes special-case handling and simplifies downstream pipelines.

Learning agents work out of the box with default memory and clearer guidance

Learning is now simpler and more effective. When learning=True, user memory is enabled by default, and the LearnedKnowledgeStore captures organizational context (goals, constraints, policies) to guide…