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/daemon/paths.rs

@@ -100,6 +100,14 @@ pub fn record_session_path() -> Result<PathBuf> {
     Ok(bsk_home()?.join("record-session.json"))
 }
 
+/// Path to a completed Trace saved before bundle export (`record-recovery.json`).
+///
+/// Kept until export succeeds so a failed `--output` write cannot drop the
+/// recording the extension already returned.
+pub fn record_recovery_path() -> Result<PathBuf> {
+    Ok(bsk_home()?.join("record-recovery.json"))
+}
+
 /// Windows named-pipe name. Include the resolved `BSK_HOME` path in the
 /// token so test homes and custom installs do not share a predictable
 /// per-username pipe.
@@ -187,6 +195,10 @@ mod tests {
                 record_session_path().unwrap(),
                 home.join("record-session.json")
             );
+            assert_eq!(
+                record_recovery_path().unwrap(),
+                home.join("record-recovery.json")
+            );
         });
     }