Saved "smart views" were feed-only; the Plex module is getting them too. Add a
`source` discriminator to saved_views ("feed" | "plex"), default "feed" so every
existing row and any source-less client stays feed. Widen the per-user unique
name constraint to (user_id, source, name) so a feed view and a Plex view can
share a name, and scope create's position numbering + the is_default "clear the
others" to (user, source).
Migration 0073 (ADD source NOT NULL server_default 'feed' + swap the unique
constraint; reversible). Endpoints: GET/POST take `source` (default feed).
Tests: source isolation, per-source default, per-source name uniqueness.
peter
fa7a09a420