fix: set the radio up for a new config before anything transmits on it

setConfig() swapped the config in and released the radio lock, and apply()
only ran later from save(), so the radio task could send queued jobs with
the new TX pin and settings on a CC1101 that wasn't set up for them.
setConfig() now swaps, saves and applies under one lock and save() goes.

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

src/Somfy.h

@@ -482,8 +482,8 @@ class Transceiver {
     bool printBuffer = false;
     //bool toJSON(JsonObject& obj);
     bool fromJSON(JsonObject& obj);
+    // Swaps in, saves and applies the config.
     void setConfig(const transceiver_config_t &cfg);
-    bool save();
     bool begin();
     void loop();
     bool end();