Saved filters and saved views

Let admins turn complex filters into named views: Untriaged this week, High votes low effort, Onboarding bugs, Pro customer requests, Stale planned, Mine, Needs changelog. Views can be private to a user or shared with the project.

Schema: saved_views(id, project_id, owner_id, name, visibility, route_scope, filters jsonb, sort jsonb, created_at). UI: save current filter, pin views in sidebar, share link, set default view. Works across feedback list, roadmap, support inbox, analytics, and timeline.