Restores LF on stream.rs, stream/tests.rs and bin/mind-stream.rs (5defa18 converted them). Renames the capped-repo test for the rule built; build_seed's since is the newest thought's label tick time; STREAM_MIN_GAP_S counts from the label, so a model run of M seconds leaves 900 - M s of quiet after admission. No behaviour change.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>