port upstream: AGC reset, autoadd max hops, noise floor EMA, fixes

- AGC reset: proper warm sleep + Calibrate(ALL) + image recal for both
  SX126x and LR1110 (was cancel+restart / no-op respectively)
- Guard AGC reset against mid-receive (matches upstream RadioLib)
- Noise floor calibration: replace blocking 64-sample burst with
  single-sample EMA (alpha=1/8) per housekeeping tick — zero blocking,
  better temporal spread for real-world noise floor tracking
- Auto-add max hops: filter new contacts by hop count (NodePrefs,
  BaseChatMesh, CompanionMesh, ZephyrDataStore persistence)
- Fix CommonCLI memcmp("prefs", 4) → 5

zephcore/helpers/CommonCLI.cpp

@@ -723,7 +723,7 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, const char* command, ch
             _prefs->advert_loc_policy = ADVERT_LOC_SHARE;
             savePrefs();
             strcpy(reply, "ok");
-        } else if (memcmp(command + 11, "prefs", 4) == 0) {
+        } else if (memcmp(command + 11, "prefs", 5) == 0) {
             _prefs->advert_loc_policy = ADVERT_LOC_PREFS;
             savePrefs();
             strcpy(reply, "ok");