Fix --exec interactive prompt bug and create comprehensive test suite

Major fixes:
- Fixed --exec entering Python REPL instead of game loop
- Resolved screenshot transparency issue (requires timer callbacks)
- Added debug output to trace Python initialization

Test suite created:
- 13 comprehensive tests covering all Python-exposed methods
- Tests use timer callback pattern for proper game loop interaction
- Discovered multiple critical bugs and missing features

Critical bugs found:
- Grid class segfaults on instantiation (blocks all Grid functionality)
- Issue #78 confirmed: Middle mouse click sends 'C' keyboard event
- Entity property setters have argument parsing errors
- Sprite texture setter returns improper error
- keypressScene() segfaults on non-callable arguments

Documentation updates:
- Updated CLAUDE.md with testing guidelines and TDD practices
- Created test reports documenting all findings
- Updated ROADMAP.md with test results and new priorities

The Grid segfault is now the highest priority as it blocks all Grid-based functionality.

src/GameEngine.cpp

@@ -63,6 +63,7 @@ GameEngine::GameEngine(const McRogueFaceConfig& cfg)
             std::cout << "Executing script: " << exec_script << std::endl;
             McRFPy_API::executeScript(exec_script.string());
         }
+        std::cout << "All --exec scripts completed" << std::endl;
     }
 
     clock.restart();
@@ -111,6 +112,7 @@ void GameEngine::setWindowScale(float multiplier)
 
 void GameEngine::run()
 {
+    std::cout << "GameEngine::run() starting main loop..." << std::endl;
     float fps = 0.0;
     clock.restart();
     while (running)

src/McRFPy_API.cpp

@@ -87,12 +87,12 @@ PyObject* PyInit_mcrfpy()
     auto t = pytypes[i];
     while (t != nullptr)
     {
-        std::cout << "Registering type: " << t->tp_name << std::endl;
+        //std::cout << "Registering type: " << t->tp_name << std::endl;
         if (PyType_Ready(t) < 0) {
             std::cout << "ERROR: PyType_Ready failed for " << t->tp_name << std::endl;
             return NULL;
         }
-        std::cout << "  tp_alloc after PyType_Ready: " << (void*)t->tp_alloc << std::endl;
+        //std::cout << "  tp_alloc after PyType_Ready: " << (void*)t->tp_alloc << std::endl;
         PyModule_AddType(m, t);
         i++;
         t = pytypes[i];
@@ -316,7 +316,9 @@ void McRFPy_API::executeScript(std::string filename)
 {
     FILE* PScriptFile = fopen(filename.c_str(), "r");
     if(PScriptFile) {
+        std::cout << "Before PyRun_SimpleFile" << std::endl;
         PyRun_SimpleFile(PScriptFile, filename.c_str());
+        std::cout << "After PyRun_SimpleFile" << std::endl;
         fclose(PScriptFile);
     }
 }

src/main.cpp

@@ -165,14 +165,21 @@ int run_python_interpreter(const McRogueFaceConfig& config, int argc, char* argv
         delete engine;
         return result;
     }
-    else if (config.interactive_mode || config.python_mode) {
-        // Interactive Python interpreter
+    else if (config.interactive_mode) {
+        // Interactive Python interpreter (only if explicitly requested with -i)
         Py_InspectFlag = 1;
         PyRun_InteractiveLoop(stdin, "<stdin>");
         Py_Finalize();
         delete engine;
         return 0;
     }
+    else if (!config.exec_scripts.empty()) {
+        // With --exec, run the game engine after scripts execute
+        engine->run();
+        Py_Finalize();
+        delete engine;
+        return 0;
+    }
     
     delete engine;
     return 0;