feat: add C API test infrastructure with foreign method binding support

Add a new test framework for exercising the Wren C embedding API directly from C code, including a Makefile target, test runner modifications, and the first API test case for boolean return values. The build system now compiles test sources from `test/api/` into a separate test executable, and the CLI's `createVM` and `runFile` functions accept an optional `WrenBindForeignMethodFn` callback to enable foreign method binding in tests. The test runner (`script/test.py`) is refactored to support both script and API test types, passing the test name instead of the full path for API tests. The initial `return_bool` test verifies that `wrenReturnBool` correctly returns `true` and `false` from foreign methods.

src/cli/main.c

@@ -9,7 +9,7 @@
 
 static int runRepl()
 {
-  WrenVM* vm = createVM();
+  WrenVM* vm = createVM(NULL);
 
   printf("\\\\/\"-\n");
   printf(" \\_/   wren v0.0.0\n");
@@ -50,7 +50,7 @@ int main(int argc, const char* argv[])
   }
   else if (argc == 2)
   {
-    runFile(argv[1]);
+    runFile(NULL, argv[1]);
   }
 
   return 0;

src/cli/vm.c

@@ -4,11 +4,11 @@
 #include "io.h"
 #include "vm.h"
 
-WrenVM* createVM()
+WrenVM* createVM(WrenBindForeignMethodFn bindForeign)
 {
   WrenConfiguration config;
 
-  config.bindForeignMethodFn = NULL;
+  config.bindForeignMethodFn = bindForeign;
   config.loadModuleFn = readModule;
 
   // Since we're running in a standalone process, be generous with memory.
@@ -22,7 +22,7 @@ WrenVM* createVM()
   return wrenNewVM(&config);
 }
 
-void runFile(const char* path)
+void runFile(WrenBindForeignMethodFn bindForeign, const char* path)
 {
   // Use the directory where the file is as the root to resolve imports
   // relative to.
@@ -42,7 +42,7 @@ void runFile(const char* path)
     exit(66);
   }
 
-  WrenVM* vm = createVM();
+  WrenVM* vm = createVM(bindForeign);
 
   WrenInterpretResult result = wrenInterpret(vm, path, source);
 

src/cli/vm.h

@@ -4,11 +4,11 @@
 #include "wren.h"
 
 // Creates a new Wren VM with the CLI's module loader and other configuration.
-WrenVM* createVM();
+WrenVM* createVM(WrenBindForeignMethodFn bindForeign);
 
 // Executes the Wren script at [path] in a new VM.
 //
 // Exits if the script failed or could not be loaded.
-void runFile(const char* path);
+void runFile(WrenBindForeignMethodFn bindForeign, const char* path);
 
 #endif