v0.50.0 — /save works again, and openagents joins the registry

/save failed with 502 every time unless you passed --force , and the cause was one missing clause. The precondition that makes a save refuse to clobber a newer revision was expressed as a HAVING on an implicit single-group aggregate — no GROUP BY . SQLite treats the whole result as one group and runs that happily; Turso's parser rejects it outright, near HAVING, "None": syntax error . The route…