build: drop vendored midi2.{h,c} and link midi2_cpp PUBLIC midi2::midi2

This is the final step of the depends=midi2 migration. Every recipe
under examples/ has been migrated to pull midi2 externally (Pico SDK
+ TinyUSB CMake via FetchContent, ESP-IDF via Component Manager,
PlatformIO via lib_deps), so the duplicated copy of dist/midi2.{h,c}
that lived under src/ no longer has any consumer.

Removes:

- src/midi2.h
- src/midi2.c

Updates the root CMakeLists.txt:

- find_package + FetchContent now ask for midi2 0.3.3 (matches the
  ESP-IDF idiom and the Library Manager constraint).
- midi2_cpp library target drops src/midi2.c from its source list.
- target_link_libraries(midi2_cpp PUBLIC midi2::midi2) exposes the
  C99 core to downstream link consumers transitively.

Bumps the manifest declarations in lockstep:

- library.properties: depends=midi2 (>=0.3.3)
- library.json:       sauloverissimo/midi2: ^0.3.3

Verified locally: cmake configure pulls midi2 v0.3.3 via
FetchContent, the host suite (7 executables, including the m2bridge
ASan + UBSan smoke) builds and runs clean.

Author: sauloverissimo

CMakeLists.txt

@@ -13,33 +13,32 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 # This is the same pattern the midi2 README documents for downstream
 # consumers, applied to midi2_cpp itself.
 if(NOT TARGET midi2)
-    find_package(midi2 0.3.2 QUIET CONFIG)
+    find_package(midi2 0.3.3 QUIET CONFIG)
     if(NOT midi2_FOUND)
         include(FetchContent)
         FetchContent_Declare(midi2
             GIT_REPOSITORY https://github.com/sauloverissimo/midi2.git
-            GIT_TAG        v0.3.2
+            GIT_TAG        v0.3.3
         )
         FetchContent_MakeAvailable(midi2)
     endif()
 endif()
 
 # Library target.
 #
-# src/midi2.c is still compiled here so the host test suite, the
-# arduino-cli compile job, and the standalone CMake build all see a
-# single coherent translation unit. The recipes under examples/ are
-# being migrated to depend on midi2::midi2 directly; once every recipe
-# has migrated, src/midi2.{h,c} will be removed and midi2_cpp will
-# link against the external midi2 target unconditionally.
+# midi2_cpp ships the C++ wrapper sources only; the C99 core lives in
+# the external midi2 target this CMakeLists pulls above. Consumers
+# linking midi2_cpp transitively see midi2::midi2 because of the
+# PUBLIC link below.
 add_library(midi2_cpp
-    src/midi2.c
     src/midi2_device.cpp
     src/midi2_ci.cpp
     src/midi2_host.cpp
     src/midi2_bridge.cpp
 )
 
+target_link_libraries(midi2_cpp PUBLIC midi2::midi2)
+
 target_include_directories(midi2_cpp
     PUBLIC
         $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src>

library.json

@@ -19,7 +19,7 @@
     "url": "https://github.com/sauloverissimo/midi2_cpp.git"
   },
   "dependencies": {
-    "sauloverissimo/midi2": "^0.3.2"
+    "sauloverissimo/midi2": "^0.3.3"
   },
   "headers": "midi2_cpp.h",
   "export": {

library.properties

@@ -8,4 +8,4 @@ category=Communication
 url=https://github.com/sauloverissimo/midi2_cpp
 architectures=*
 includes=midi2_cpp.h
-depends=midi2 (>=0.3.2)
+depends=midi2 (>=0.3.3)