Portable text search: case-insensitive contains and LIKE escaping #83

Signal

We want portable helpers for text match: contains, startsWith, endsWith and ilike. They escape % and _ in the value, and they work the same on every dialect.

Why (MyRemotely)

• 60 contains: and 23 mode: insensitive filters. Examples: search by tenant name, address and phone.
• The dialects differ. Postgres has ILIKE. SQLite LIKE ignores case only for ASCII. MySQL depends on the collation. The helper must document what "insensitive" means on each one, or use lower() on both sides.

Part of #52: the CAFE-stack roadmap signal from MyRemotely. This shows the direction we want, and it is not a demand. We can send a PR if you accept the idea.