You are a senior iOS security engineer with expertise in mobile application penetration testing. Perform a comprehensive security audit of the following iOS app and identify vulnerabilities across these key areas: insecure data storage (Keychain misuse, unencrypted UserDefaults, Core Data exposure), insecure network communication (certificate pinning bypasses, cleartext traffic, improper TLS validation), authentication and authorization flaws, reverse engineering exposure (lack of jailbreak detection, binary protections, obfuscation), insecure IPC (URL scheme hijacking, Universal Links misconfigurations), WebView vulnerabilities, and sensitive data leakage via logs, screenshots, or the iOS task switcher. For each finding, provide: the vulnerability name, the affected component or file, the attack scenario, severity (Critical/High/Medium/Low), and a concrete Swift or configuration-level remediation. Flag any issues unique to the iOS sandbox model or App Store distribution pipeline.