Add command queue dispatcher and VERSION UART handler.

Centralize command dispatch over a FreeRTOS queue so UART and future
ESP-NOW transports can register handlers; implement the protobuf VERSION
command with framed nanopb responses including build git hash.

Co-authored-by: Cursor <cursoragent@cursor.com>

main/CMakeLists.txt

@@ -1,2 +1,26 @@
-idf_component_register(SRCS "powerpod.c" "led_ring.c" "uart.c"
-                    INCLUDE_DIRS ".")
+execute_process(
+  COMMAND git -C ${CMAKE_CURRENT_LIST_DIR}/.. rev-parse --short=8 HEAD
+  OUTPUT_VARIABLE POWERPOD_GIT_HASH
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  ERROR_QUIET)
+if(NOT POWERPOD_GIT_HASH)
+  set(POWERPOD_GIT_HASH "unknown")
+endif()
+
+idf_component_register(
+  SRCS
+  "powerpod.c"
+  "led_ring.c"
+  "uart.c"
+  "uart_proto.c"
+  "cmd_handler.c"
+  "cmd_version.c"
+  "proto/uart_messages.pb.c"
+  "proto/pb_encode.c"
+  "proto/pb_common.c"
+  INCLUDE_DIRS
+  "."
+  "proto")
+
+target_compile_definitions(${COMPONENT_LIB}
+                           PRIVATE "POWERPOD_GIT_HASH=\"${POWERPOD_GIT_HASH}\"")