feat(repeater): suppress Adaptive Power Control while relaying

A repeater wants full, consistent TX power for relay reach, and APC's feedback
(own ACKs / own flood echoes) never fires on forwarded traffic — so leaving APC
on would relay at whatever reduced power it last trimmed to, or sit inert on a
dedicated repeater network. Force it off whenever client_repeat is on, mirroring
the power-save lock:

- apcActive() = tx_apc && !client_repeat gates every APC control site
  (sample/failure/track).
- applyApc() pins power to the tx_power_dbm ceiling; called at boot, on the
  on-device repeater toggle, and on the app's CMD_SET_RADIO_PARAMS.
- Settings "Auto pwr" shows "--" and blocks the toggle while repeating; the
  user's pref is preserved and restored when the repeater is switched off.

Also refreshes the FEATURES repeater entry (Hold-Enter reset, Errors row, schema
0x10, the radio-setting locks and status indicator).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

examples/companion_radio/MyMesh.h

@@ -156,6 +156,11 @@ protected:
   // Overhear suppression only makes sense while repeating; gated behind its own
   // opt-in pref (Settings > Radio > Suppress dup).
   bool wantsOverhearSuppress() const override { return _prefs.client_repeat && _prefs.repeat_suppress_dup; }
+  // Adaptive Power Control is suppressed while repeating: a repeater wants full,
+  // consistent TX power for relay reach, and its feedback sources (own ACKs /
+  // own flood echoes) don't fire on forwarded traffic anyway. applyApc() then
+  // pins power to the ceiling.
+  bool apcActive() const { return _prefs.tx_apc && !_prefs.client_repeat; }
 
   void sendFloodScoped(const TransportKey& scope, mesh::Packet* pkt, uint32_t delay_millis);
   void sendFloodScoped(const ContactInfo& recipient, mesh::Packet* pkt, uint32_t delay_millis=0) override;