test: Implement Computational Budget assertion in Grid Pooling tests

Recent performance optimizations in the Grid revealed that significant regressions (e.g., 7000+ redundant render calls) can occur silently without affecting the VDOM delta output or breaking functional tests.

Goal: Enhance test/playwright/unit/grid/Pooling.spec.mjs to enforce a "Computational Budget".

Tasks:

1. Inject a spy into Neo.grid.column.Component.prototype.cellRenderer within the test environment.
2. Count the number of executions during a controlled vertical scroll operation.
3. Assert that the execution count stays within an acceptable limit (e.g., < 100 for a 10-row scroll), effectively creating a performance regression guard.

This will catch "silent heaters" where the App Worker performs excessive work that is filtered out before reaching the Main Thread.