Add cookbook examples with updated callback signatures for #229, #230

Cookbook structure:
- lib/: Reusable component library (Button, StatBar, AnimationChain, etc.)
- primitives/: Demo apps for individual components
- features/: Demo apps for complex features (animation chaining, shaders)
- apps/: Complete mini-applications (calculator, dialogue system)
- automation/: Screenshot capture utilities

API signature updates applied:
- on_enter/on_exit/on_move callbacks now only receive (pos) per #230
- on_cell_enter/on_cell_exit callbacks only receive (cell_pos) per #230
- Animation chain library uses Timer-based sequencing (unaffected by #229)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/cookbook/run_screenshots.py

@@ -0,0 +1,135 @@
+#!/usr/bin/env python3
+"""Capture all cookbook screenshots.
+
+This script captures screenshots for all demos in the cookbook.
+Run with:
+    cd build && ./mcrogueface --headless --exec ../tests/cookbook/run_screenshots.py
+
+Output goes to:
+    tests/cookbook/screenshots/
+        primitives/
+        features/
+        apps/
+        compound/
+"""
+import mcrfpy
+from mcrfpy import automation
+import sys
+import os
+
+# Add cookbook to path
+COOKBOOK_DIR = os.path.dirname(os.path.abspath(__file__))
+sys.path.insert(0, COOKBOOK_DIR)
+
+# Output directories
+SCREENSHOT_BASE = os.path.join(COOKBOOK_DIR, "screenshots")
+
+
+def ensure_dirs():
+    """Create screenshot directories."""
+    dirs = ["primitives", "features", "apps", "compound"]
+    for d in dirs:
+        os.makedirs(os.path.join(SCREENSHOT_BASE, d), exist_ok=True)
+
+
+def capture_demo(module_path, output_name, category):
+    """Capture a single demo screenshot.
+
+    Args:
+        module_path: Dotted module path (e.g., "primitives.demo_button")
+        output_name: Output filename without extension
+        category: Subdirectory (e.g., "primitives")
+
+    Returns:
+        True if successful, False otherwise
+    """
+    try:
+        # Import the module
+        parts = module_path.rsplit('.', 1)
+        if len(parts) == 2:
+            parent, name = parts
+            module = __import__(module_path, fromlist=[name])
+        else:
+            module = __import__(module_path)
+
+        # Find the Demo class
+        demo_class = None
+        for attr_name in dir(module):
+            attr = getattr(module, attr_name)
+            if isinstance(attr, type) and 'Demo' in attr_name:
+                demo_class = attr
+                break
+
+        if not demo_class:
+            print(f"  No Demo class in {module_path}")
+            return False
+
+        # Create and activate demo
+        demo = demo_class()
+        demo.activate()
+
+        # Take screenshot
+        output_path = os.path.join(SCREENSHOT_BASE, category, f"{output_name}.png")
+        automation.screenshot(output_path)
+        print(f"  OK: {output_path}")
+        return True
+
+    except Exception as e:
+        print(f"  FAIL: {module_path} - {e}")
+        return False
+
+
+def main():
+    """Main screenshot capture routine."""
+    print("=" * 60)
+    print("McRogueFace Cookbook - Screenshot Capture")
+    print("=" * 60)
+
+    ensure_dirs()
+
+    # Define all demos to capture
+    demos = [
+        # Primitives
+        ("primitives.demo_button", "button", "primitives"),
+        ("primitives.demo_stat_bar", "stat_bar", "primitives"),
+        ("primitives.demo_choice_list", "choice_list", "primitives"),
+        ("primitives.demo_text_box", "text_box", "primitives"),
+        ("primitives.demo_toast", "toast", "primitives"),
+        ("primitives.demo_drag_drop_frame", "drag_drop_frame", "primitives"),
+        ("primitives.demo_drag_drop_grid", "drag_drop_grid", "primitives"),
+        ("primitives.demo_click_pickup", "click_pickup", "primitives"),
+
+        # Features
+        ("features.demo_animation_chain", "animation_chain", "features"),
+        ("features.demo_shaders", "shaders", "features"),
+        ("features.demo_rotation", "rotation", "features"),
+
+        # Apps
+        ("apps.calculator", "calculator", "apps"),
+        ("apps.dialogue_system", "dialogue_system", "apps"),
+
+        # Compound
+        ("compound.shop_demo", "shop_demo", "compound"),
+    ]
+
+    success = 0
+    failed = 0
+
+    for module_path, output_name, category in demos:
+        print(f"\nCapturing: {output_name}")
+        if capture_demo(module_path, output_name, category):
+            success += 1
+        else:
+            failed += 1
+
+    print("\n" + "=" * 60)
+    print(f"Complete! Success: {success}, Failed: {failed}")
+    print(f"Screenshots saved to: {SCREENSHOT_BASE}")
+    print("=" * 60)
+
+    sys.exit(0 if failed == 0 else 1)
+
+
+if __name__ == "__main__":
+    # Use a timer to ensure the scene system is ready
+    mcrfpy.Timer("run_capture", lambda rt: main(), 50)