chore(playground): refresh vendored WASM bundle with SQLR-6 engine (#165)

Rebuild sdk/wasm (wasm-pack --target web --release) against the engine
at 79eff1d so the /playground exposes aggregates / GROUP BY / DISTINCT /
HAVING over JOIN results. Only the .wasm binary changes — the JS glue
and type definitions are byte-identical (no API surface change).

Verified by loading the vendored pkg directly and running joined
GROUP BY / DISTINCT / HAVING queries (correct results incl. outer-join
NULL handling).

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

Author: joaoh82