fix(record): recover failed Trace exports and hint --url when the default start page fails

Reject legacy JSON --output before recording starts, persist the completed Trace before writing the bundle so `bsk record stop --output <dir>` can retry after an export failure, and tell users to pass --url when https://example.com/ does not load.

crates/bsk-cli/src/cli/mod.rs

@@ -22,6 +22,7 @@ pub mod navigate;
 pub mod network;
 pub mod observe;
 pub mod record;
+pub mod record_recovery;
 pub mod record_state;
 pub mod render_error;
 pub mod screenshot;