refactor: rewrite filter system with native macOS controls

[datlechin]

Summary

• Native macOS controls: Replace custom Menu dropdowns with Picker(.menu) (NSPopUpButton), remove card-style row backgrounds, use borderless +/− buttons following NSPredicateEditor pattern
• Remove quick search: Delete "search all columns" feature entirely (QuickSearchField, buildQuickSearchQuery, buildCombinedQuery from protocol + all 8 plugins). Raw SQL filter row is the default instead
• Fix filter persistence bugs: saveLastFilters now uses appliedFilters (not editing state), clearAll() resets visibility, restoreLastFilters only shows panel when valid applied filters exist
• Clean architecture: Remove per-row checkboxes, "Select All", separate footer. Move Unset/Apply to header bar. Merge presets/settings/SQL preview into single options menu
• HIG compliance: Accessibility labels, reduce motion support, MixedStateCheckbox (NSViewRepresentable), flexible SQL preview sheet, theme typography throughout
• Navigation fix: Tables with active filters/sorting/edits open in new tab instead of replacing current tab

Test plan

• Open filter panel (Cmd+F) → auto-adds empty Raw SQL row with focus
• Type WHERE clause → press Enter → filters applied, data reloads
• Click +/− to add/remove filter rows
• Remove last filter row → panel closes, data reloads if filters were applied
• Click Unset → clears all filters, closes panel, reloads data
• Apply filter → close panel → close tab → reopen table → filters restored (with "Restore Last Filter" setting)
• Apply filter → Unset → close tab → reopen → NO filters restored
• Open filter panel without applying → close tab → reopen → NO panel shown
• Switch between tabs → filter state preserved per tab
• Filter a table → click another table in sidebar → opens new tab (not replace)
• FK navigation → auto-applies equality filter on target table
• Context menu "Duplicate Filter" and "Remove Filter" work
• AND/OR picker appears only with 2+ filters
• Options menu (⋯): SQL preview, presets, settings all accessible