deps: move json/httplib to CPM

cmake/dependencies/httplib.cmake

@@ -0,0 +1,55 @@
+# cpp-httplib dependency management
+
+if(EMSCRIPTEN)
+  set(YAZE_HTTPLIB_TARGETS "" CACHE INTERNAL "cpp-httplib targets")
+  return()
+endif()
+
+include(cmake/CPM.cmake)
+include(cmake/dependencies.lock)
+
+message(STATUS "Setting up cpp-httplib ${HTTPLIB_VERSION}")
+
+set(_YAZE_USE_SYSTEM_HTTPLIB ${YAZE_USE_SYSTEM_DEPS})
+
+# Try to use system packages first
+if(_YAZE_USE_SYSTEM_HTTPLIB)
+  find_package(httplib QUIET)
+  if(httplib_FOUND)
+    message(STATUS "Using system httplib")
+    set(YAZE_HTTPLIB_TARGETS httplib::httplib CACHE INTERNAL "cpp-httplib targets")
+    return()
+  elseif(YAZE_USE_SYSTEM_DEPS)
+    message(WARNING "System httplib not found despite YAZE_USE_SYSTEM_DEPS=ON; falling back to CPM download")
+  endif()
+endif()
+
+CPMAddPackage(
+  NAME httplib
+  VERSION ${HTTPLIB_VERSION}
+  GITHUB_REPOSITORY yhirose/cpp-httplib
+  GIT_TAG v${HTTPLIB_VERSION}
+  OPTIONS
+    "HTTPLIB_INSTALL OFF"
+    "HTTPLIB_TEST OFF"
+    "HTTPLIB_COMPILE OFF"
+    "HTTPLIB_USE_OPENSSL_IF_AVAILABLE OFF"
+    "HTTPLIB_USE_ZLIB_IF_AVAILABLE OFF"
+    "HTTPLIB_USE_BROTLI_IF_AVAILABLE OFF"
+    "HTTPLIB_USE_ZSTD_IF_AVAILABLE OFF"
+)
+
+# Verify target is available
+if(TARGET httplib::httplib)
+  message(STATUS "httplib::httplib target found")
+elseif(TARGET httplib)
+  add_library(httplib::httplib ALIAS httplib)
+  message(STATUS "Created httplib::httplib alias")
+else()
+  message(FATAL_ERROR "httplib target not found after CPM fetch")
+endif()
+
+set(YAZE_HTTPLIB_TARGETS httplib::httplib)
+set(YAZE_HTTPLIB_TARGETS httplib::httplib CACHE INTERNAL "cpp-httplib targets")
+
+message(STATUS "cpp-httplib setup complete")