Complete Phase 1: Build KiCad with optional dependencies disabled

Add CMake override modules, stub implementations, and patches to build
KiCad without CURL, libgit2, OpenCASCADE, and ngspice dependencies.

- cmake/: Find modules that provide stub targets when deps disabled
- stubs/include/: Header stubs for curl, git2, ngspice, OCC
- stubs/src/: Implementation stubs for disabled features
- patches/: Consolidated patch for KiCad source modifications
- scripts/: Build helper scripts

Verified full native build on macOS with all optional deps disabled.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

CMakeLists.txt

@@ -0,0 +1,51 @@
+#
+# KiCad WebAssembly Port - Root Build Configuration
+#
+# This is a wrapper CMakeLists.txt that configures optional dependencies
+# before building KiCad. Use this for building with features disabled.
+#
+# Usage:
+#   mkdir build && cd build
+#   cmake .. -DKICAD_USE_CURL=OFF -DKICAD_USE_GIT=OFF -DKICAD_USE_OCC=OFF
+#   make -j$(nproc)
+#
+
+cmake_minimum_required(VERSION 3.22)
+project(kicad-wasm-wrapper)
+
+# Add our stubs to the include path when dependencies are disabled
+set(KICAD_WASM_STUBS_DIR "${CMAKE_CURRENT_SOURCE_DIR}/stubs/include")
+
+# Include our options module
+include("${CMAKE_CURRENT_SOURCE_DIR}/cmake/KicadWasmOptions.cmake")
+
+# Add stubs to include path when features are disabled
+if(NOT KICAD_USE_CURL OR NOT KICAD_USE_GIT)
+    message(STATUS "Adding stub headers to include path: ${KICAD_WASM_STUBS_DIR}")
+    include_directories(BEFORE SYSTEM "${KICAD_WASM_STUBS_DIR}")
+endif()
+
+# For now, we need to build KiCad from its directory directly
+# because it expects to be the root project.
+#
+# This wrapper is mainly for documentation and can be extended later.
+message(STATUS "")
+message(STATUS "=== KiCad Wasm Build Configuration ===")
+message(STATUS "")
+message(STATUS "Note: KiCad must be built from its source directory.")
+message(STATUS "")
+message(STATUS "To build with features disabled, use:")
+message(STATUS "")
+message(STATUS "  cd kicad")
+message(STATUS "  mkdir build && cd build")
+message(STATUS "  cmake .. \\")
+message(STATUS "    -DCMAKE_MODULE_PATH=${CMAKE_CURRENT_SOURCE_DIR}/cmake \\")
+message(STATUS "    -DKICAD_USE_CURL=${KICAD_USE_CURL} \\")
+message(STATUS "    -DKICAD_USE_GIT=${KICAD_USE_GIT} \\")
+message(STATUS "    -DKICAD_USE_OCC=${KICAD_USE_OCC} \\")
+message(STATUS "    -DKICAD_USE_NGSPICE=${KICAD_USE_NGSPICE}")
+message(STATUS "")
+message(STATUS "Or use the helper script:")
+message(STATUS "  ./scripts/build.sh")
+message(STATUS "")
+message(FATAL_ERROR "Please build from kicad/ directory as described above")