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.

tests/api_timer_test.py

@@ -0,0 +1,70 @@
+#!/usr/bin/env python3
+"""Test for mcrfpy.setTimer() and delTimer() methods"""
+import mcrfpy
+import sys
+
+def test_timers():
+    """Test timer API methods"""
+    print("Testing mcrfpy timer methods...")
+    
+    # Test 1: Create a simple timer
+    try:
+        call_count = [0]
+        def simple_callback(runtime):
+            call_count[0] += 1
+            print(f"Timer callback called, count={call_count[0]}, runtime={runtime}")
+        
+        mcrfpy.setTimer("test_timer", simple_callback, 100)
+        print("✓ setTimer() called successfully")
+    except Exception as e:
+        print(f"✗ setTimer() failed: {e}")
+        print("FAIL")
+        return
+    
+    # Test 2: Delete the timer
+    try:
+        mcrfpy.delTimer("test_timer")
+        print("✓ delTimer() called successfully")
+    except Exception as e:
+        print(f"✗ delTimer() failed: {e}")
+        print("FAIL")
+        return
+    
+    # Test 3: Delete non-existent timer (should not crash)
+    try:
+        mcrfpy.delTimer("nonexistent_timer")
+        print("✓ delTimer() accepts non-existent timer names")
+    except Exception as e:
+        print(f"✗ delTimer() failed on non-existent timer: {e}")
+        print("FAIL")
+        return
+    
+    # Test 4: Create multiple timers
+    try:
+        def callback1(rt): pass
+        def callback2(rt): pass
+        def callback3(rt): pass
+        
+        mcrfpy.setTimer("timer1", callback1, 500)
+        mcrfpy.setTimer("timer2", callback2, 750)
+        mcrfpy.setTimer("timer3", callback3, 250)
+        print("✓ Multiple timers created successfully")
+        
+        # Clean up
+        mcrfpy.delTimer("timer1")
+        mcrfpy.delTimer("timer2")
+        mcrfpy.delTimer("timer3")
+        print("✓ Multiple timers deleted successfully")
+    except Exception as e:
+        print(f"✗ Multiple timer test failed: {e}")
+        print("FAIL")
+        return
+    
+    print("\nAll timer API tests passed")
+    print("PASS")
+
+# Run the test
+test_timers()
+
+# Exit cleanly
+sys.exit(0)