Feed filters and the default-saved-view mirror lived under shared localStorage keys, so one
account's view (incl. its starred default) leaked into another account signed into the same
browser — visible with per-tab accounts as a fresh account showing the previous account's
'N active' filters instead of a clean default.
Key both by the tab's active account (siftlode.filters.<id> / siftlode.defaultViewFilters.<id>);
load a tab's filters from its own account on login/switch/add, falling back to defaults when the
account isn't known yet. A share link's filters still win and are persisted to the account. The
old shared keys are simply no longer read (a one-time reset to defaults on the first load after
this change; migrating them would risk re-leaking across accounts).
59de0ffdfd