Unit tests for QML Pickers and Selectors

[parvathyabnair]

unit tests in tests/qml/ for active pickers and selectors:

DateRangeSelector.qml (date bounds and range pick)
DaySelector.qml (day selection signals)
DateRangeHeaderFilter.qml (filter toggle and active range text)
FilterableHeaderContents.qml (filter state integration)
SelectionButton.qml (selection state and click)
StatusSelector.qml (status changes and badge color)
InlineOptionSelector.qml (radio-style option selection)
MultiAssigneeSelector.qml (multi-select IDs array output)
WorkItemSelector.qml (project and task selection logic)
ProjectStageSelector.qml (stage list per project)
StageFilterMenu.qml (stage filter menu toggling)
AssigneeFilterMenu.qml (assignee filter menu toggling)

[suraj-yadav0]

Address these changes in the Test cases , Few Test Cases were removed , And Few Test Cases are brittle.

[suraj-yadav0]

All requested changes have been addressed. Tests restored, date bounds stabilized, and UI interactions properly verified. All 601 QML unit tests pass.