fix: skip the room records too when a restore leaves the shades out

A restore without "shades" skipped the shade and group records but not
the room records, which come first, so it read the repeaters and the
settings from room data. The skip is now shadeModelBytes(), in a
ConfigHeader.h the native tests can reach, which counts rooms, shades
and groups. Found during LOOP_QUEUE_PLAN.md's review.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/ConfigFile.cpp

@@ -574,10 +574,8 @@ bool ShadeConfigFile::restoreFile(SomfyShadeController *s, const char *filename,
   }
   else {
     ESP_LOGI(TAG, "Shade data ignored");
-    // FF past the shades and groups.
-    this->file.seek(this->file.position()
-      + (this->header.shadeRecords * this->header.shadeRecordSize)
-      + (this->header.groupRecords * this->header.groupRecordSize), SeekSet);  // Start at the beginning of the file after the header.
+    // FF past the rooms, shades and groups.
+    this->file.seek(this->file.position() + shadeModelBytes(this->header), SeekSet);
   }
   if(opts.repeaters) {
     ESP_LOGI(TAG, "Restoring Repeaters...");