Add ViewDefinition/ViewFile types, extend SidebarSelection with 'view'
kind. Client-side filter evaluation in viewFilters.ts with full operator
support. VIEWS section in sidebar (hidden when empty). Wire view loading
through useVaultLoader, NoteList, and filterEntries pipeline.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
