Prefer Connect libp2p watchless mode with WatchService fallback

[robinbraemer]

Summary

• parse managed libp2p bootstrap headers from the authenticated WatchService websocket response
• start the Connect libp2p endpoint from WatchService-provided edge/relay addresses so users do not need libp2p env vars for managed mode
• advertise the watchless endpoint capability only when Moxy sends Connect-Libp2p-Capabilities: session,status,watchless
• prefer watchless mode only after libp2p registration commits and the initial status report succeeds
• keep WatchService as the compatibility and health fallback when Moxy is old, libp2p is unavailable, registration closes, or repeated status reports fail
• keep env-based/manual libp2p startup compatible and default it to legacy session,status capabilities

Verification

• ./gradlew --no-daemon --console=plain :core:test --tests com.minekube.connect.tunnel.p2p.Libp2pWatchlessControllerTest --tests com.minekube.connect.register.WatcherRegisterTest
• ./gradlew --no-daemon --console=plain :core:test
• ./gradlew --no-daemon --console=plain build
• git diff --check