Fix stale cmd/ scripts, export LoginWithChromedp, clean up vet warnings

Update 5 cmd/ test utilities that referenced APIs that drifted after
bridge refactors (NewBrowserAuthManager, bridge.NewConfig, changed
function signatures). Rewrite test-kosmi and test-native to use
NewGraphQLWSClient directly. Export LoginWithChromedp for use by cmd
scripts. Fix redundant-newline vet warnings across 5 cmd/ files.
Remove unreachable code and replace deprecated ioutil calls in
bridge/helper/lottie_convert.go.

Made-with: Cursor

cmd/extract-queries/main.go

@@ -36,7 +36,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	fmt.Println("=== WebSocket Messages ===\n")
+	fmt.Println("\n=== WebSocket Messages ===")
 
 	for _, entry := range har.Log.Entries {
 		for i, msg := range entry.WebSocketMessages {