node-sqlite3-wasm compatibility fallback

Chose lazy node-sqlite3-wasm for Node 18–22.14 over better-sqlite3 because externalizing the fallback preserves the standalone SEA binary’s no-runtime-dependencies and zero-byte-overhead constraints; SEA embeds modern Node and always uses node:sqlite. The fallback cannot use WAL and is slower under concurrency, which is acceptable only for the single-process CLI; modern Node or the standalone binary remains preferred.