b2d4afd408
- Add date_range_picker() component with enable/disable checkbox - Add searchable_dropdown() component with search, select all, clear - Implement filter_section() with layout for dates and multi-selects - Add comprehensive state management in AppState: - Filter toggle states (initiated_filter_enabled, last_seen_filter_enabled) - Date values for both ranges - Dropdown visibility state - Selection state for drugs, indications, directorates - Search text state for filtering options - Event handlers for all filter interactions - Computed vars for filtered options and selection counts - Style components using design tokens from styles.py - Debounced handlers deferred to Phase 3.3 (Filter Logic)