Thread cacheDir through NewClient -> RunOniOS -> MobileDependency.TempDir
so the iOS client can pass its sandbox-writable cache directory for
debug bundle zip file creation instead of os.TempDir().
Move log collection into platform-dispatched addPlatformLog():
- iOS: adds the file-based Go client log (with rotation, stderr/stdout
companions and anonymization handled by addLogfile) plus the Swift app
log (swift-log.log) written by the iOS app into the same log directory
- Other non-Android platforms: existing file-based log + systemd fallback
Narrow the debug_nonandroid.go build tag to !android && !ios so iOS no
longer attempts the systemd journal fallback.
Add a DebugBundle() entry point to the iOS Go client that generates a
bundle, uploads it and returns the upload key. It works with or without
a running engine: when the engine is up it reuses the live config, sync
response and client metrics; otherwise it loads the config from disk (or
the preloaded tvOS config). Guard the live config/ConnectClient behind a
state mutex since DebugBundle may run on a different thread.
