* [client] Support embed.Client on Android with netstack mode
embed.Client.Start() calls ConnectClient.Run() which passes an empty
MobileDependency{}. On Android, the engine dereferences nil fields
(IFaceDiscover, NetworkChangeListener, DnsReadyListener) causing panics.
Provide complete no-op stubs so the engine's existing Android code
paths work unchanged — zero modifications to engine.go:
- Add androidRunOverride hook in Run() for Android-specific dispatch
- Add runOnAndroidEmbed() with complete MobileDependency (all stubs)
- Wire default stubs via init() in connect_android_default.go:
noopIFaceDiscover, noopNetworkChangeListener, noopDnsReadyListener
- Forward logPath to c.run()
Tested: embed.Client starts on Android arm64, joins mesh via relay,
discovers peers, localhost proxy works for TCP+UDP forwarding.
* [client] Fix TestServiceParamsPath for Windows path separators
Use filepath.Join in test assertions instead of hardcoded POSIX paths
so the test passes on Windows where filepath.Join uses backslashes.
