Objective:
Create a new Playwright unit test suite (test/playwright/unit/grid/Pooling.spec.mjs) dedicated to verifying the correctness and performance of the Grid's Row and Cell Pooling mechanisms ("Fixed-DOM-Order").

Goals:

1. Strict Delta Verification:

   • Validate that scrolling (vertical, horizontal, diagonal) generates ZERO structural DOM deltas (moveNode, insertNode, removeNode) for pooled elements (rows/cells).
   • Confirm that updates are restricted to lightweight attributes (e.g., transform, textContent, aria-rowindex).

2. Edge Case Coverage:

   • Vertical Scroll: Verify row recycling.
   • Horizontal Scroll: Verify cell recycling (especially with locked columns).
   • Diagonal Scroll: Verify simultaneous row/cell recycling.
   • Buffer Range: Verify pooling logic correctly handles the start/end of the dataset (clamping).

3. Performance Auditing:

   • Assert that the number of deltas matches the expected minimum (e.g., if 5 rows recycle, exactly 5 row updates + cell content updates).
   • Challenge the system to ensure no redundant updates occur (e.g., updating hidden pool rows).

Why:
The current Teleportation.spec.mjs touches on this but is mixed with other concerns. A dedicated suite will serve as a regression guard for the critical "Fixed-DOM-Order" performance architecture.