[AsafMah]

Description

Adds TableView.ApplyColumnFilterImmediately (default false). When it's on, a column's filter applies as soon as the user changes it in the filter flyout: checking or unchecking an item, using Select All, or typing in the search box. The flyout's OK and Cancel buttons are hidden, and closing the flyout keeps the filter.

Each change applies exactly what pressing OK would apply at that moment (ColumnHeader.ApplyFilter()), so the filtering semantics don't change; only the timing does. Details:

• Select All sets every item at once and applies once, not once per item.
• The Select All checkbox also follows the items programmatically, and on open. Those updates don't count as user changes and don't re-apply the filter.
• The flyout clears its search box when it closes. That clear is ignored, so it doesn't undo a filter applied from the search.

Related Issue

None opened; happy to open one or move this to a discussion if you'd prefer.

Type of Change

• 🐛 Bug fix
• ✨ New feature
• 📝 Documentation update
• ♻️ Refactor
• 🧪 Test
• 🔧 Chore / maintenance

Checklist

• This PR is not from my main branch
• Tested with WinUI target (builds and runs in an app with the option on; the flyout interaction not yet exercised by hand)
• Tested with Uno Platform target (not tested; the change is in shared code)
• Unit / integration tests added or updated (none yet; the flyout's internals aren't reachable from the existing tests without new seams. Happy to add them if you can point me at the preferred approach.)
• Documentation updated to reflect changes (filtering.md)
• Code follows the project's coding conventions

🤖 Generated with Claude Code