CUB-230: ESP32 offline status buffering and replay on reconnect

- Add SPIFFS buffer for status entries when MQTT offline
- FIFO eviction when max_buffer_entries exceeded
- Replay buffer on MQTT reconnect
- Configurable buffer size in esp32-config.json

firmware/platformio.ini

@@ -44,8 +44,7 @@ board_build.flash_mode = dio
 board_build.f_cpu = 160000000L
 build_src_filter =
     +<../lib/>
-    +<esp8266-camera-bridge.cpp>
-    -<*.cpp>
+    +<*.cpp>
 
 ; ── ESP32: MQTT Bridge ─────────────────────────────────────
 ; Flashed onto ESP32 Dev Board. Connects to travel router,
@@ -64,4 +63,6 @@ build_flags = ${common.build_flags}
 build_src_filter =
     +<../lib/>
     +<esp32-mqtt-bridge.cpp>
-    -<*.cpp>
+    -<esp8266-*.cpp>
+    -<test-*.cpp>
+    -<*.h>