Fix KiCad WASM build and runtime errors

Build improvements:
- Change -O0 to -O1 to fix "local count too large" asyncify error
- Add wasm-emscripten-finalize to host (Docker OOMs on large WASM)
- Use -gseparate-dwarf for smaller main binary with debug info
- Build native protoc for code generation
- Add more functions to asyncify removelist

Runtime fixes:
- Add inject-dyncall-shims.sh to fix "dynCall_* is not defined" in Emscripten 4.x
- Update wxwidgets with browserInfo.name fix

New stubs and bindings:
- Add Embind bindings for JavaScript interop
- Add stubs for scripting, API plugin, PCB frame, navlib

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

wasm/bindings/pcbnew_embind.cpp

@@ -0,0 +1,86 @@
+/*
+ * Embind bindings for KiCad WASM
+ * Exposes core PCBnew objects to JavaScript
+ *
+ * This provides a foundation for future Pyodide integration.
+ *
+ * Note: GetBoard() is not available when KICAD_SCRIPTING=OFF.
+ * These bindings expose the classes for use when a board reference
+ * is obtained through other means (e.g., from the UI).
+ */
+
+#ifdef __EMSCRIPTEN__
+#include <emscripten/bind.h>
+#include <board.h>
+#include <footprint.h>
+#include <pad.h>
+#include <vector>
+
+using namespace emscripten;
+
+// Wrapper to return footprints as vector for JS iteration
+std::vector<FOOTPRINT*> Board_GetFootprints(BOARD* board) {
+    if (!board) return {};
+    std::vector<FOOTPRINT*> result;
+    for (FOOTPRINT* fp : board->Footprints()) {
+        result.push_back(fp);
+    }
+    return result;
+}
+
+// Wrapper to return pads as vector
+std::vector<PAD*> Footprint_GetPads(FOOTPRINT* fp) {
+    if (!fp) return {};
+    std::vector<PAD*> result;
+    for (PAD* pad : fp->Pads()) {
+        result.push_back(pad);
+    }
+    return result;
+}
+
+// Wrapper for GetFileName since it returns wxString
+std::string Board_GetFileName(BOARD* board) {
+    if (!board) return "";
+    return board->GetFileName().ToStdString();
+}
+
+// Wrapper for footprint reference
+std::string Footprint_GetReference(FOOTPRINT* fp) {
+    if (!fp) return "";
+    return fp->GetReference().ToStdString();
+}
+
+// Wrapper for footprint value
+std::string Footprint_GetValue(FOOTPRINT* fp) {
+    if (!fp) return "";
+    return fp->GetValue().ToStdString();
+}
+
+// Wrapper for pad number
+std::string Pad_GetNumber(PAD* pad) {
+    if (!pad) return "";
+    return pad->GetNumber().ToStdString();
+}
+
+// Wrapper for pad pin function
+std::string Pad_GetPinFunction(PAD* pad) {
+    if (!pad) return "";
+    return pad->GetPinFunction().ToStdString();
+}
+
+EMSCRIPTEN_BINDINGS(pcbnew) {
+    // Register vector types for iteration
+    register_vector<FOOTPRINT*>("FootprintVector");
+    register_vector<PAD*>("PadVector");
+
+    // Helper functions that operate on pointers
+    // Note: GetBoard() not available - will be added when Pyodide integration is done
+    function("Board_GetFootprints", &Board_GetFootprints, allow_raw_pointers());
+    function("Board_GetFileName", &Board_GetFileName, allow_raw_pointers());
+    function("Footprint_GetPads", &Footprint_GetPads, allow_raw_pointers());
+    function("Footprint_GetReference", &Footprint_GetReference, allow_raw_pointers());
+    function("Footprint_GetValue", &Footprint_GetValue, allow_raw_pointers());
+    function("Pad_GetNumber", &Pad_GetNumber, allow_raw_pointers());
+    function("Pad_GetPinFunction", &Pad_GetPinFunction, allow_raw_pointers());
+}
+#endif