Revert on-disk layout to the one before 1.16.0 merge

When "flood_max_unscoped" and "flood_max_advert" were inserted at offsets
291-292 in a previous commit, they displaced "fan_mode" and "fan_timeout_secs"
from their established positions.  On upgrade, devices with existing saved
prefs would load the old "fan_mode" byte (0, 1, or 2) into "flood_max_unscoped"
and the low byte of "fan_timeout_secs" into "flood_max_advert", both yielding
values of 0 or 1.  A "flood_max_unscoped" or "flood_max_advert" of 0 or 1
effectively silences the repeater, causing it to drop nearly all unscoped
flood and advert packets.  Additionally, "rx_boosted_gain" was displaced to
offset 291 in the new layout, causing it to read 0 (gain disabled) on devices
whose prefs were saved before the layout change.

Restore a correct, upgrade-safe layout:

  290: reserved_290  (placeholder; preserves the byte that held
                      rx_boosted_gain in the layout before this series)
  291: rx_boosted_gain
  292: fan_mode
  293-294: fan_timeout_secs  (uint16_t)
  295: flood_max_unscoped
  296: flood_max_advert

"flood_max_unscoped" and "flood_max_advert" are moved to the end so that
existing saved prefs with "fan_mode"/"fan_timeout_secs" at 291-294 are
read correctly on upgrade, and the repeater resumes normal flood forwarding
behaviour.

Also fix a copy-paste bug in loadPrefsInt where the availability
checks for "flood_max_unscoped" and "flood_max_advert" both used
sizeof(rx_boosted_gain) instead of their own field sizes.

src/helpers/CommonCLI.cpp

@@ -88,22 +88,25 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
     file.read((uint8_t *)&_prefs->discovery_mod_timestamp, sizeof(_prefs->discovery_mod_timestamp)); // 162
     file.read((uint8_t *)&_prefs->adc_multiplier, sizeof(_prefs->adc_multiplier));                 // 166
     file.read((uint8_t *)_prefs->owner_info, sizeof(_prefs->owner_info));                          // 170
-    if (file.available() >= (int)sizeof(_prefs->rx_boosted_gain)) {
-      file.read((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));            // 290
-    }
-    if (file.available() >= (int)sizeof(_prefs->rx_boosted_gain)) {
-      file.read((uint8_t *)&_prefs->flood_max_unscoped, sizeof(_prefs->flood_max_unscoped));      // 291
+    if (file.available() >= (int)sizeof(_prefs->reserved_290)) {
+      file.read((uint8_t *)&_prefs->reserved_290, sizeof(_prefs->reserved_290));                  // 290 reserved
     }
     if (file.available() >= (int)sizeof(_prefs->rx_boosted_gain)) {
-      file.read((uint8_t *)&_prefs->flood_max_advert, sizeof(_prefs->flood_max_advert));          // 292
+      file.read((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));            // 291
     }
     if (file.available() >= (int)sizeof(_prefs->fan_mode)) {
-      file.read((uint8_t *)&_prefs->fan_mode, sizeof(_prefs->fan_mode));                          // 293
+      file.read((uint8_t *)&_prefs->fan_mode, sizeof(_prefs->fan_mode));                          // 292
     }
     if (file.available() >= (int)sizeof(_prefs->fan_timeout_secs)) {
-      file.read((uint8_t *)&_prefs->fan_timeout_secs, sizeof(_prefs->fan_timeout_secs));          // 294
+      file.read((uint8_t *)&_prefs->fan_timeout_secs, sizeof(_prefs->fan_timeout_secs));          // 293
+    }
+    if (file.available() >= (int)sizeof(_prefs->flood_max_unscoped)) {
+      file.read((uint8_t *)&_prefs->flood_max_unscoped, sizeof(_prefs->flood_max_unscoped));      // 295
+    }
+    if (file.available() >= (int)sizeof(_prefs->flood_max_advert)) {
+      file.read((uint8_t *)&_prefs->flood_max_advert, sizeof(_prefs->flood_max_advert));          // 296
     }
-    // next: 296
+    // next: 297
 
     // sanitise bad pref values
     _prefs->rx_delay_base = constrain(_prefs->rx_delay_base, 0, 20.0f);
@@ -195,12 +198,13 @@ void CommonCLI::savePrefs(FILESYSTEM* fs) {
     file.write((uint8_t *)&_prefs->discovery_mod_timestamp, sizeof(_prefs->discovery_mod_timestamp)); // 162
     file.write((uint8_t *)&_prefs->adc_multiplier, sizeof(_prefs->adc_multiplier));                 // 166
     file.write((uint8_t *)_prefs->owner_info, sizeof(_prefs->owner_info));                          // 170
-    file.write((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));              // 290
-    file.write((uint8_t *)&_prefs->flood_max_unscoped, sizeof(_prefs->flood_max_unscoped));        // 291
-    file.write((uint8_t *)&_prefs->flood_max_advert, sizeof(_prefs->flood_max_advert));            // 292
-    file.write((uint8_t *)&_prefs->fan_mode, sizeof(_prefs->fan_mode));                            // 293
-    file.write((uint8_t *)&_prefs->fan_timeout_secs, sizeof(_prefs->fan_timeout_secs));            // 294
-    // next: 296
+    file.write((uint8_t *)&_prefs->reserved_290, sizeof(_prefs->reserved_290));                    // 290 reserved
+    file.write((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));              // 291
+    file.write((uint8_t *)&_prefs->fan_mode, sizeof(_prefs->fan_mode));                            // 292
+    file.write((uint8_t *)&_prefs->fan_timeout_secs, sizeof(_prefs->fan_timeout_secs));            // 293
+    file.write((uint8_t *)&_prefs->flood_max_unscoped, sizeof(_prefs->flood_max_unscoped));        // 295
+    file.write((uint8_t *)&_prefs->flood_max_advert, sizeof(_prefs->flood_max_advert));            // 296
+    // next: 297
 
     file.close();
   }