feat(repeater): default network profile, band-matched to companion freq

Enabling the repeater now defaults to a dedicated radio profile rather
than relaying on the companion's current frequency: same-network
repeating isn't the MeshCore community norm. The default profile is
seeded with a frequency in the same legal band as the companion's own
network (433/868/915 MHz, via defaultRepeaterFreqForBand()) rather than
a flat firmware constant, so it can't land outside what's allowed for
the operator's region.

Also fixes a gap where a true first boot (no prefs file yet) never hit
the DataStore.cpp migration fallback and stayed on repeater_use_profile=0.

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

examples/companion_radio/DataStore.cpp

@@ -356,16 +356,23 @@ void DataStore::loadPrefsInt(const char *filename, NodePrefs& _prefs, double& no
   rd(&_prefs.repeater_bw,          sizeof(_prefs.repeater_bw));
   rd(&_prefs.repeater_sf,          sizeof(_prefs.repeater_sf));
   rd(&_prefs.repeater_cr,          sizeof(_prefs.repeater_cr));
-  // Pre-0x10 files leave stray sentinel bytes here. If the profile fields aren't a
-  // valid radio config, force the profile off so the repeater can't switch to junk.
+  // Pre-0x10 files leave stray sentinel bytes here, same as a never-configured
+  // device. Either way there's no valid saved profile, so default to a profile
+  // in the same band as the companion's own network (_prefs.freq, already read
+  // above) rather than "Current" — a repeater silently following the companion
+  // onto whatever private network it later joins isn't the MeshCore community
+  // norm; that stays opt-in. Band-matched rather than a flat frequency so the
+  // default can't land outside what's legal where the companion is set up.
   if (_prefs.repeater_use_profile > 1) _prefs.repeater_use_profile = 0;
   if (!(_prefs.repeater_freq >= 100.0f && _prefs.repeater_freq <= 960.0f
         && _prefs.repeater_sf >= 5 && _prefs.repeater_sf <= 12
         && _prefs.repeater_cr >= 5 && _prefs.repeater_cr <= 8
         && _prefs.repeater_bw >= 7.0f && _prefs.repeater_bw <= 510.0f)) {
-    _prefs.repeater_use_profile = 0;
-    _prefs.repeater_freq = _prefs.repeater_bw = 0.0f;
-    _prefs.repeater_sf = _prefs.repeater_cr = 0;
+    _prefs.repeater_use_profile = 1;
+    _prefs.repeater_freq = defaultRepeaterFreqForBand(_prefs.freq);
+    _prefs.repeater_bw   = LORA_BW;
+    _prefs.repeater_sf   = LORA_SF;
+    _prefs.repeater_cr   = LORA_CR;
   }
   // → 0xC0DE000B: append bot_commands_enabled + quiet-hours. Older files leave
   // stray bytes here; clamp so upgraders fall back to off / no quiet hours.

examples/companion_radio/MyMesh.cpp

@@ -1307,6 +1307,14 @@ MyMesh::MyMesh(mesh::Radio &radio, mesh::RNG &rng, mesh::RTCClock &rtc, SimpleMe
   _prefs.bw = LORA_BW;
   _prefs.cr = LORA_CR;
   _prefs.tx_power_dbm = LORA_TX_POWER;
+  // Repeater profile default for a true first boot (no prefs file yet, so
+  // loadPrefs() below is a no-op) — same band-matched seed as the upgrade
+  // path in DataStore.cpp, kept in sync rather than left at memset's 0/Current.
+  _prefs.repeater_use_profile = 1;
+  _prefs.repeater_freq = defaultRepeaterFreqForBand(_prefs.freq);
+  _prefs.repeater_bw   = LORA_BW;
+  _prefs.repeater_sf   = LORA_SF;
+  _prefs.repeater_cr   = LORA_CR;
   _prefs.gps_enabled = 0;       // GPS disabled by default
   _prefs.gps_interval = 0;      // No automatic GPS updates by default
   _prefs.display_brightness = 2; // medium brightness by default

examples/companion_radio/MyMesh.h

@@ -41,18 +41,7 @@ class UITask;
 
 /* ---------------------------------- CONFIGURATION ------------------------------------- */
 
-#ifndef LORA_FREQ
-#define LORA_FREQ 915.0
-#endif
-#ifndef LORA_BW
-#define LORA_BW 250
-#endif
-#ifndef LORA_SF
-#define LORA_SF 10
-#endif
-#ifndef LORA_CR
-#define LORA_CR 5
-#endif
+// LORA_FREQ/BW/SF/CR fallbacks now live in NodePrefs.h (DataStore.cpp needs them too).
 #ifndef LORA_TX_POWER
 #define LORA_TX_POWER 20
 #endif

examples/companion_radio/NodePrefs.h

@@ -2,6 +2,37 @@
 #include <cstdint>
 #include <stdio.h>
 
+// Firmware's own boot-default radio params — used both as the companion's
+// initial freq/sf/bw/cr (MyMesh.cpp) and, here, as the seed for a never-
+// configured repeater profile (DataStore.cpp). Kept above any per-board
+// target.h include so a board can still override via -D before this file
+// is reached.
+#ifndef LORA_FREQ
+#define LORA_FREQ 915.0
+#endif
+#ifndef LORA_BW
+#define LORA_BW 250
+#endif
+#ifndef LORA_SF
+#define LORA_SF 10
+#endif
+#ifndef LORA_CR
+#define LORA_CR 5
+#endif
+
+// Bucket a companion frequency into whichever of the three license-exempt
+// bands MeshCore's app-driven repeat toggle historically restricted to (see
+// repeat_freq_ranges in MyMesh.cpp: 433.000 / 869.495 / 918.000 MHz). Used to
+// seed a never-configured repeater profile in the same legal band as the
+// companion's own network (MyMesh.cpp begin(), DataStore.cpp) — a flat
+// single frequency could land outside the bands allowed where the operator
+// actually lives.
+static inline float defaultRepeaterFreqForBand(float companion_freq) {
+  if (companion_freq < 500.0f) return 433.000f;
+  if (companion_freq < 890.0f) return 869.495f;
+  return 918.000f;
+}
+
 #define TELEM_MODE_DENY            0
 #define TELEM_MODE_ALLOW_FLAGS     1     // use contact.flags
 #define TELEM_MODE_ALLOW_ALL       2
@@ -176,7 +207,11 @@ struct NodePrefs {  // persisted to file
   // Optional dedicated radio profile for repeater mode. When repeater_use_profile
   // is 1, enabling the repeater switches the radio to repeater_freq/bw/sf/cr and
   // disabling restores the companion's freq/bw/sf/cr (the fields above). 0 = the
-  // repeater stays on the current companion frequency (default — no switch).
+  // repeater stays on the current companion frequency. Default (a never-configured
+  // device) is 1, seeded via defaultRepeaterFreqForBand(freq) + LORA_SF/BW/CR —
+  // repeating on whatever private network the companion later joins isn't the
+  // community norm, and the seed stays in the same legal band as the companion's
+  // own network rather than a flat frequency.
   uint8_t  repeater_use_profile;
   float    repeater_freq;
   float    repeater_bw;

examples/companion_radio/ui-new/RepeaterScreen.h

@@ -6,10 +6,14 @@
 // and keeps the relaying controls next to the numbers that show them working.
 //
 // Network modes:
-//  - Current  — repeat on the companion's current frequency (default).
+//  - Current  — repeat on the companion's current frequency. Opt-in only:
+//               relaying on whatever network the operator is chatting on
+//               isn't the MeshCore community norm.
 //  - Custom   — enabling the repeater switches the radio to a dedicated profile
 //               (preset or manual), and disabling restores the companion params.
-//               Set the profile equal to the companion's for "same network".
+//               Default for a never-configured device, seeded with a frequency
+//               in the same band as the companion's own network (so the default
+//               can't land outside what's legal for the operator's region).
 // Included by UITask.cpp.
 
 #include <helpers/ui/DisplayDriver.h>