Add wxWidgets 3.2.6 submodule and wxBase WASM build script

- Add wxWidgets v3.2.6 as git submodule for wxBase utilities
- Create build-wxbase-wasm.sh script to compile wxBase for Emscripten
- Disable WASM-incompatible features: zlib, expat, xlocale, fswatcher
- Successfully builds libwx_baseu-3.2-Emscripten.a (3.1MB)

This provides wxString, wxFile, wxDateTime and other base utilities
needed for the KiCad board data model without GUI dependencies.

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

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

.gitmodules

@@ -1,3 +1,6 @@
 [submodule "kicad"]
 	path = kicad
 	url = git@github.com:VV-EE/kicad-source-mirror.git
+[submodule "wxwidgets"]
+	path = wxwidgets
+	url = https://github.com/wxWidgets/wxWidgets.git

scripts/build-wxbase-wasm.sh

@@ -0,0 +1,67 @@
+#!/bin/bash
+# Build wxBase (non-GUI wxWidgets) for WebAssembly
+# This builds only the base utilities needed by KiCad core (wxString, wxFile, etc.)
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="$(dirname "$SCRIPT_DIR")"
+BUILD_DIR="$PROJECT_ROOT/build-wasm/wxwidgets"
+WX_SOURCE="$PROJECT_ROOT/wxwidgets"
+
+echo "=== Building wxBase for WASM ==="
+echo "Project root: $PROJECT_ROOT"
+echo "Build dir: $BUILD_DIR"
+echo "wxWidgets source: $WX_SOURCE"
+
+# Verify we're in the right place
+if [ ! -f "$WX_SOURCE/CMakeLists.txt" ]; then
+    echo "ERROR: wxWidgets source not found at $WX_SOURCE"
+    echo "Make sure the wxwidgets submodule is initialized"
+    exit 1
+fi
+
+# Clean if requested (must be before mkdir to properly reset CMake cache)
+if [ "$1" = "--clean" ]; then
+    echo "Cleaning build directory..."
+    rm -rf "$BUILD_DIR"
+fi
+
+# Create build directory
+mkdir -p "$BUILD_DIR"
+cd "$BUILD_DIR"
+
+# Configure with emcmake
+# Disable all GUI and most optional features - we only need wxBase utilities
+# Note: zlib/expat "builtin" versions use POSIX file descriptors not available in WASM,
+# so we disable them. We'll use Emscripten's ports if compression is needed.
+emcmake cmake "$WX_SOURCE" \
+    -DwxUSE_GUI=OFF \
+    -DwxBUILD_SHARED=OFF \
+    -DwxBUILD_SAMPLES=OFF \
+    -DwxBUILD_TESTS=OFF \
+    -DwxBUILD_DEMOS=OFF \
+    -DwxBUILD_BENCHMARKS=OFF \
+    -DwxUSE_REGEX=OFF \
+    -DwxUSE_ZLIB=OFF \
+    -DwxUSE_EXPAT=OFF \
+    -DwxUSE_LIBJPEG=OFF \
+    -DwxUSE_LIBPNG=OFF \
+    -DwxUSE_LIBTIFF=OFF \
+    -DwxUSE_WEBREQUEST=OFF \
+    -DwxUSE_SECRETSTORE=OFF \
+    -DwxUSE_LIBSDL=OFF \
+    -DwxUSE_LIBMSPACK=OFF \
+    -DwxUSE_FSWATCHER=OFF \
+    -DwxUSE_XLOCALE=OFF \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DCMAKE_POLICY_VERSION_MINIMUM=3.5
+
+# Build
+echo ""
+echo "=== Building ==="
+emmake make -j$(nproc 2>/dev/null || sysctl -n hw.ncpu)
+
+echo ""
+echo "=== Build complete ==="
+ls -lh "$BUILD_DIR"/lib/*.a 2>/dev/null || echo "Libraries built in $BUILD_DIR"

wxwidgets

@@ -0,0 +1 @@
+Subproject commit 5ff25322553c1870cf20a2e1ba6f20ed50d9fe9a