Feat: UI Filtering Logic

[tobiu]

This task focuses on connecting the UI Controls to the Grid's Store to enable real-time filtering.

Requirements

1. Search Filter: Connect the "Search User" text field in ControlsContainer to filter the store by login or name.
2. Activity Filter (Logic): Add a filter logic to the Store to filter users based on contribution count (e.g., >1000 total).
3. UI Updates: Update the "Visible: X" label when filters change.

Acceptance Criteria

• Typing in the search box updates the grid in real-time (buffered).
• The row count label updates accurately.