perf(grid): compile LIKE/ILIKE RegExp once per filter, not per row

[ZhuchkaTriplesix]

Summary

grid_filter_engine builds _likeToRegExp(...) inside the per-row evaluation for LIKE / NOT LIKE / ILIKE / NOT ILIKE. A 5000-row scan recompiles the same pattern 5000 times (AST depth × rows). Filter bar is already debounced 150ms; the scan itself is still O(R × regex compile).

Scope

• Compile the LIKE regex at parse / bind time and reuse it in the evaluator.
• Tests: LIKE %foo% still matches; case sensitivity for ILIKE unchanged.