Agent notes

Use the versions in .tool-versions: Elixir 1.20.4 (OTP 29) and Erlang 29.1.2.
mix precommit is the project alias; it runs compile with warnings as errors, deps.unlock --unused, format check, then tests. It does not run Credo; run mix credo --strict separately when checking lint.
Run a focused test with mix test test/feed_reader/<name>_test.exs (or pass a test line filter with mix test path:line). Test-only helpers and fake transports live in test/support/ and are compiled only in the test environment.
FeedReader is the public API. Parsing is event-stream based; built-in formats are tried in RSS, Atom, RDF order, and custom formats are supplied per call and implement FeedReader.Format.
Remote stream sessions own downloaded temporary files. Fully consuming the event stream cleans them up; if enumeration stops early, call FeedReader.close/1 (typically in after). Local-file sessions leave the caller's source file untouched.