relay doesn't validate since field on commit events? #1357
Description
relay seems to accept since being an empty string, when everywhere else it uses null:
{"t": "#commit", "op": 1}, {"ops": [], "rev": "3mgdycfub2y22", "seq": 10331293478, "repo": "did:plc:jq3zvrb5ewg2qgup73qsouze", "time": "2026-03-05T15:47:54.716328Z", "blobs": [], "since": "", "blocks": h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commit": 42(h'00017112202568EFEB8DA6CF2F8FDED90971928C73082C2FEBD844E0FDD5771A6FEDFEAE11'), "rebase": false, "tooBig": false}
(the seq is on relay.fire.hose.cam, and that did's pds doesn't work right now so not sure which one it is)
if the relay isn't rejecting on an empty string (which is an invalid TID) i'm guessing it doesn't reject on other strings either?