fix(plugin-cassandra): browse tables without an OFFSET, which CQL does not have

[yordis]

• Opening any table on a Cassandra or ScyllaDB connection fails with line 1:NN : Syntax error, because the table browser sends LIMIT n OFFSET m and CQL has no OFFSET.
• Both engines now declare the leading-rows pagination that Cloudflare R2 SQL already uses, so a browse reads the first page and never asks the server to skip rows.

Checklist:

• Tests added or updated
• CHANGELOG.md updated under [Unreleased]
• Docs updated in docs/ if the change affects user-facing behavior (no page describes Cassandra pagination today)
• User-facing strings localized (no new strings)
• No SwiftLint violations