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>

scripts/prepare.sh

@@ -0,0 +1,120 @@
+#!/bin/bash
+#
+# KiCad Wasm Port - Prepare Script
+#
+# This script applies patches to the KiCad source code to enable
+# building with optional dependencies disabled.
+#
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="$(dirname "$SCRIPT_DIR")"
+KICAD_DIR="$PROJECT_ROOT/kicad"
+PATCHES_DIR="$PROJECT_ROOT/patches"
+
+echo "=== KiCad Wasm Port - Prepare ==="
+echo "Project root: $PROJECT_ROOT"
+echo "KiCad source: $KICAD_DIR"
+echo ""
+
+# Check if kicad submodule is initialized
+if [ ! -f "$KICAD_DIR/CMakeLists.txt" ]; then
+    echo "Error: KiCad submodule not initialized."
+    echo "Run: git submodule update --init --recursive"
+    exit 1
+fi
+
+# Check if patches directory exists
+if [ ! -d "$PATCHES_DIR" ]; then
+    echo "Error: Patches directory not found: $PATCHES_DIR"
+    exit 1
+fi
+
+# Function to check if a patch is already applied
+patch_already_applied() {
+    local patch_file="$1"
+    # Try to reverse-apply the patch (dry run)
+    # If it succeeds, the patch is already applied
+    cd "$KICAD_DIR"
+    if git apply --reverse --check "$patch_file" 2>/dev/null; then
+        return 0
+    else
+        return 1
+    fi
+}
+
+# Function to apply a patch
+apply_patch() {
+    local patch_file="$1"
+    local patch_name="$(basename "$patch_file")"
+
+    echo "Checking patch: $patch_name"
+
+    if patch_already_applied "$patch_file"; then
+        echo "  -> Already applied, skipping"
+        return 0
+    fi
+
+    echo "  -> Applying..."
+    cd "$KICAD_DIR"
+
+    # Try to apply the patch
+    if git apply --check "$patch_file" 2>/dev/null; then
+        git apply "$patch_file"
+        echo "  -> Success"
+    else
+        echo "  -> Warning: Patch may not apply cleanly, trying with -3 (three-way merge)"
+        if git apply -3 "$patch_file" 2>/dev/null; then
+            echo "  -> Success with three-way merge"
+        else
+            echo "  -> Error: Patch failed to apply"
+            echo "     You may need to manually resolve conflicts or update the patch"
+            return 1
+        fi
+    fi
+}
+
+# Apply all patches in order
+echo "Applying patches..."
+echo ""
+
+patch_count=0
+patch_failed=0
+
+for patch_file in "$PATCHES_DIR"/*.patch; do
+    if [ -f "$patch_file" ]; then
+        if apply_patch "$patch_file"; then
+            ((patch_count++))
+        else
+            ((patch_failed++))
+        fi
+        echo ""
+    fi
+done
+
+echo "=== Summary ==="
+echo "Patches applied: $patch_count"
+echo "Patches failed: $patch_failed"
+
+if [ $patch_failed -gt 0 ]; then
+    echo ""
+    echo "Some patches failed to apply. Please check the errors above."
+    exit 1
+fi
+
+echo ""
+echo "=== Next Steps ==="
+echo ""
+echo "Build with optional dependencies disabled:"
+echo ""
+echo "  mkdir build && cd build"
+echo "  cmake ../kicad \\"
+echo "    -DKICAD_USE_CURL=OFF \\"
+echo "    -DKICAD_USE_GIT=OFF \\"
+echo "    -DKICAD_USE_OCC=OFF \\"
+echo "    -DKICAD_USE_NGSPICE=OFF \\"
+echo "    -DCMAKE_PREFIX_PATH=\"\$(pwd)/../stubs/include\""
+echo "  make -j\$(nproc)"
+echo ""
+echo "Done!"