Fix PT-P710BT raster protocol handling and add regression coverage.

Align print command payload generation with model-specific protocol requirements, add verbose CLI diagnostics and robust status retries, and introduce protocol regression tests to prevent future GF/ESC i z regressions.

Made-with: Cursor

CMakeLists.txt

@@ -25,6 +25,7 @@ configure_file(
 set(LIBPTOUCH_SOURCES
 	src/lib/libptouch_core.c
 	src/lib/libptouch_usb.c
+	src/lib/libptouch_protocol.c
 	src/lib/libptouch_layout.c
 	src/lib/libptouch_media_info.c
 	src/lib/libptouch_trim.c
@@ -74,6 +75,19 @@ if(NOT MSVC)
 	target_compile_options(ptouch-print PRIVATE -Wall -Wextra -Wpedantic)
 endif()
 
+enable_testing()
+add_executable(ptouch-protocol-regression-test
+	tests/protocol_regression_test.c
+	src/lib/libptouch_protocol.c
+)
+target_include_directories(ptouch-protocol-regression-test PRIVATE
+	"${CMAKE_CURRENT_SOURCE_DIR}/src/lib"
+)
+if(NOT MSVC)
+	target_compile_options(ptouch-protocol-regression-test PRIVATE -Wall -Wextra -Wpedantic)
+endif()
+add_test(NAME protocol_regression_test COMMAND ptouch-protocol-regression-test)
+
 install(TARGETS ptouch ARCHIVE DESTINATION "${CMAKE_INSTALL_LIBDIR}")
 install(TARGETS ptouch_shared LIBRARY DESTINATION "${CMAKE_INSTALL_LIBDIR}"
 	RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}")