fix: advertise studio profiles in desktop handshake supported_profiles

Same fix as Android — the CallOffer now includes STUDIO_64K/48K/32K
so the relay can negotiate studio quality levels.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/wzp-client/src/handshake.rs

@@ -38,6 +38,9 @@ pub async fn perform_handshake(
         ephemeral_pub,
         signature,
         supported_profiles: vec![
+            QualityProfile::STUDIO_64K,
+            QualityProfile::STUDIO_48K,
+            QualityProfile::STUDIO_32K,
             QualityProfile::GOOD,
             QualityProfile::DEGRADED,
             QualityProfile::CATASTROPHIC,