Fennek v1.7.0

✨ Added

• "+ New Channel" UI for joining hashtag channels — a "► New Channel" row at the top of the chat list opens a join screen (keyboard types the #name, PSK derived from it, persisted to channels.txt on SD; jumps straight into the new channel after joining).

🔄 Changed

• Robust time synchronization without a hardware RTC. Canonical clock is now ESP32 system time (SystemRTCClock), which survives deep sleep. New services/timesync coordinator: opportunistic NTP (when Wi-Fi is up) + a top-up before auto-standby, with Mesh adverts as a passive source. Quality model (estErr = learned drift × time since sync) with exponential back-off, s_clockConfident bootstrap for the first advert after boot, POSIX time zone (default Europe/Berlin incl. DST), settings rows "Time zone"/"Time", and console time / time set / time sync / tz.

📋 Full history: CHANGELOG.md