feat(schematic): eeschema WASM build + e2e harness

wasm/stubs/ngspice/sharedspice.h

@@ -0,0 +1,55 @@
+/*
+ * Minimal stub of ngspice's sharedspice.h for KiCad WASM builds.
+ *
+ * Only the type names referenced by kicad/eeschema/sim/ngspice.{h,cpp} need
+ * to exist. The eeschema sim layer compiles but the simulator frame is never
+ * instantiated in WASM (FRAME_SIMULATOR's try/catch in IFACE::CreateKiWindow
+ * catches the init failure and returns nullptr).
+ *
+ * We intentionally do NOT define NGSPICE_PACKAGE_VERSION so that ngspice.h's
+ * fallback `typedef bool NG_BOOL;` (line 46) provides the boolean type.
+ */
+
+#ifndef KICAD_WASM_NGSPICE_SHAREDSPICE_STUB_H
+#define KICAD_WASM_NGSPICE_SHAREDSPICE_STUB_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct ngcomplex {
+    double cx_real;
+    double cx_imag;
+} ngcomplex_t;
+
+struct vector_info {
+    char*        v_name;
+    int          v_type;
+    short        v_flags;
+    double*      v_realdata;
+    ngcomplex_t* v_compdata;
+    int          v_length;
+};
+
+typedef struct vector_info* pvector_info;
+
+/* Opaque payload types for callbacks we never wire up (SendData/SendInitData). */
+typedef struct vecvaluesall* pvecvaluesall;
+typedef struct vecinfoall*   pvecinfoall;
+
+/*
+ * Function types (not pointers). ngspice.h references them as `SendChar*` etc.,
+ * so the trailing star in the typedef site makes the pointer.
+ */
+typedef int (SendChar)(char*, int, void*);
+typedef int (SendStat)(char*, int, void*);
+typedef int (ControlledExit)(int, bool, bool, int, void*);
+typedef int (SendData)(pvecvaluesall, int, int, void*);
+typedef int (SendInitData)(pvecinfoall, int, void*);
+typedef int (BGThreadRunning)(bool, int, void*);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* KICAD_WASM_NGSPICE_SHAREDSPICE_STUB_H */