test: cover the frame codec and command names

Builds SomfyFrame.cpp in the native env, with a minimal String and
no-op ESP_LOGx in the stubs, and tests:

- a fixed 56-bit frame, byte for byte, so what goes on air is pinned
- encode/decode round trips for 56-bit, 80-bit (repeats, Favorite,
  Stop, steps, Toggle), RTW and RTV frames
- rejection of bad checksums, addresses, rolling codes, keys and
  80-bit parity
- repeat/synonym tracking in copy()
- parsing and naming of commands

The command-name round trip fails: names the firmware reports, such as
"Step Up" and "My+Up", parse back to the wrong command.

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

test/stubs/esp_log.h

@@ -0,0 +1,10 @@
+// Logging stand-in for the native test env.  The format arguments are never
+// evaluated so tests stay quiet and logging can't affect what they check.
+#ifndef esp_log_stub_h
+#define esp_log_stub_h
+#define ESP_LOGE(tag, ...) ((void)(tag))
+#define ESP_LOGW(tag, ...) ((void)(tag))
+#define ESP_LOGI(tag, ...) ((void)(tag))
+#define ESP_LOGD(tag, ...) ((void)(tag))
+#define ESP_LOGV(tag, ...) ((void)(tag))
+#endif