Production uses pgxstore, whose plain scs.Store.Find deliberately panics
("missing context arg") — only FindCtx works. DedupeSessionCookies called
Store.Find directly, so any request carrying duplicate session cookies
500'd (chi Recoverer caught the panic). Unit tests passed because the
in-memory store implements plain Find.
Mirror scs.doStoreFind: type-assert FindCtx(context.Context, string) and
use it with the request context, falling back to plain Find for simple
stores. Regression test adds a ctx-only store whose plain methods panic.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
greeneclipseandClaude Fable 5
c9554f2f7c