motion(workspace): eliminate layout jumps using QueryaAnimatedExpand in Data Grid toolbars & panels #707

Problem

Per the Fluid Morphing & Fluid UI design guidelines, UI surfaces must preserve spatial continuity and should never abruptly pop into existence or snap away in a single frame.

In the current Workspace and Data Grid implementation, several collapsible toolbars and panels insert/remove themselves via hard boolean checks, causing abrupt layout jumps (40px, 26px, 340px) that shift the entire virtual grid:

1. Staging Toolbar (DataGridStagingToolbar)

   • File: lib/features/workspace/results_tab.dart:229-235
   • When stagingBuffer != null on the first cell modification, the toolbar snaps into the column layout, shifting the entire grid down by ~40px in a single frame.
   • Fix: Wrap with QueryaAnimatedExpand(expanded: widget.stagingBuffer != null, child: DataGridStagingToolbar(...)) using QueryaMotion.treeExpand.

2. Quick Filter Bar (DataGridFilterBar)

   • File: lib/features/workspace/results_tab.dart:370-381
   • Toggling the filter bar via Ctrl+F / Cmd+F or Esc immediately expands/collapses the bar without height morphing.
   • Fix: Wrap with QueryaAnimatedExpand.

3. Selection Calc Bar (DataGridCalcBar)

   • File: lib/features/workspace/data_grid_calc_bar.dart:17-19
   • When selecting a single cell, DataGridCalcBar returns SizedBox.shrink() (height 0). As soon as a 2nd cell is selected, it immediately jumps to height: 26. Deselecting snaps it back to 0. This causes continuous 26px vertical jitter during normal grid navigation and selection.
   • Fix: Animate height transition smoothly between 0 and 26px with QueryaMotion.fast / QueryaMotion.enter.

4. Value Inspector Side Panel (DataGridValuePanel)

   • File: lib/features/workspace/results_tab.dart:442-464
   • When toggled, the 340px side panel snaps in, instantly squishing the grid horizontally.
   • Fix: Animate width expansion (0px ↔ 340px) using AnimatedSize or slide-over drawer behavior.

5. Groupings Sub-grid (DataGridGroupingsView)

   • File: lib/features/workspace/data_grid_groupings_view.dart:384-395
   • Expanding an aggregation row immediately injects a 220px subgrid (if (isExpanded)).
   • Fix: Wrap the sub-grid in QueryaAnimatedExpand.

Acceptance Criteria

• Staging toolbar expands and collapses smoothly when staging buffer changes between dirty/clean/null
• Quick filter bar expands and collapses with height animation
• Selection calc bar does not cause grid height jitter when selection alternates between 1 and 2+ cells
• Value inspector panel expands smoothly on the right edge
• Groupings sub-grids morph height smoothly via QueryaAnimatedExpand
• All animations respect QueryaMotionScope (reduced/off motion)