Kysely: JSON-path traversal injection via unsanitized path-leg metacharacters in `JSONPathBuilder.key()` / `.at()`

Summary Kysely 0.28.12 added a sanitizeStringLiteral call inside DefaultQueryCompiler.visitJSONPathLeg commit 0a602bf, PR 1727 to fix CVE-2026-32763 GHSA-wmrf-hv6w-mr66. The fix only doubles single quotes ' → ''; it does not escape JSON-path metacharacters ., , , , , ?. When attacker-controlled...