v1.37.0-beta.3

Fixes

• Restore p2p.radio as default station — removing it in beta.2 broke station update checks for all clients (no preferred station = station path skipped entirely)
• Unified update polling — both station implementations use shared UpdateMirrorUtils.fetchReleases() to fetch stable + beta releases in one call
• Beta channel support — station serves beta releases via ?channel=beta or ?prerelease=true query parameters
• Station UI cleanup — remove FAB, simplify actions card, log storage slider
• DM conversations in Chat app — past 1:1 conversations visible even when other party is offline