Remove deprecated registerPyAction/registerInputAction system (closes #2, closes #3)

This is our largest net-negative commit yet\! Removed the entire deprecated
action registration system that provided unnecessary two-step indirection:
keyboard → action string → Python callback

Removed components:
- McRFPy_API::_registerPyAction() and _registerInputAction() methods
- McRFPy_API::callbacks map for storing Python callables
- McRFPy_API::doAction() method for executing callbacks
- ACTIONPY macro from Scene.h for detecting "_py" suffixed actions
- Scene::registerActionInjected() and unregisterActionInjected() methods
- tests/api_registerPyAction_issue2_test.py (tested deprecated functionality)

The game now exclusively uses keypressScene() for keyboard input handling,
which is simpler and more direct. Also commented out the unused _camFollow
function that referenced non-existent do_camfollow variable.

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

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

tests/api_registerPyAction_issue2_test.py

@@ -1,90 +0,0 @@
-#!/usr/bin/env python3
-"""Test for registerPyAction - Related to issue #2 (review necessity)"""
-import mcrfpy
-from mcrfpy import automation
-from datetime import datetime
-
-action_calls = {"test_action": 0, "another_action": 0}
-
-def test_action_handler():
-    """Handler for test_action"""
-    action_calls["test_action"] += 1
-    print(f"test_action called: {action_calls['test_action']} times")
-
-def another_action_handler():
-    """Handler for another_action"""
-    action_calls["another_action"] += 1
-    print(f"another_action called: {action_calls['another_action']} times")
-
-def test_registerPyAction():
-    """Test registerPyAction functionality (Alpha Blocker Issue #2)"""
-    print("Testing registerPyAction (Issue #2 - Review necessity)...")
-    print("This is marked as an Alpha Blocker - may need removal")
-    
-    # Register actions
-    try:
-        mcrfpy.registerPyAction("test_action", test_action_handler)
-        print("✓ Registered test_action")
-        
-        mcrfpy.registerPyAction("another_action", another_action_handler)
-        print("✓ Registered another_action")
-    except Exception as e:
-        print(f"✗ registerPyAction failed: {e}")
-        print("FAIL")
-        return
-    
-    # Test registerInputAction to map keys to actions
-    try:
-        # These are SFML key codes - may need adjustment
-        mcrfpy.registerInputAction(0, "test_action")  # Key A
-        mcrfpy.registerInputAction(1, "another_action")  # Key B
-        print("✓ Registered input mappings")
-    except Exception as e:
-        print(f"✗ registerInputAction failed: {e}")
-    
-    # Note: In headless mode, we can't easily trigger these actions
-    # They would normally be triggered by keyboard input
-    
-    print("\nAnalysis for Issue #2:")
-    print("- registerPyAction allows mapping string names to Python callbacks")
-    print("- registerInputAction maps keyboard codes to action strings")
-    print("- This creates a two-step indirection: key -> action string -> callback")
-    print("- Modern approach might be direct key -> callback mapping")
-    print("- Or use keypressScene() for all keyboard handling")
-    
-    # Try to trigger actions programmatically if possible
-    # This depends on internal implementation
-    
-    def check_results(runtime):
-        print(f"\nAction call counts:")
-        print(f"- test_action: {action_calls['test_action']}")
-        print(f"- another_action: {action_calls['another_action']}")
-        
-        if action_calls["test_action"] > 0 or action_calls["another_action"] > 0:
-            print("✓ Actions were triggered")
-        else:
-            print("✗ No actions triggered (expected in headless mode)")
-        
-        # Take screenshot
-        timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
-        filename = f"test_registerPyAction_issue2_{timestamp}.png"
-        automation.screenshot(filename)
-        print(f"Screenshot saved: {filename}")
-        print("PASS - Test completed, Issue #2 needs review for removal")
-        
-        mcrfpy.delTimer("check_results")
-    
-    # In headless mode, run synchronously
-    print("\nAction call counts:")
-    print(f"- test_action: {action_calls['test_action']}")
-    print(f"- another_action: {action_calls['another_action']}")
-    
-    print("✗ No actions triggered (expected in headless mode)")
-    print("PASS - Test completed, Issue #2 needs review for removal")
-
-# Run test directly in headless mode
-test_registerPyAction()
-
-# Exit cleanly
-import sys
-sys.exit(0)