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/features/__init__.py

@@ -0,0 +1,9 @@
+# McRogueFace Cookbook - Feature Demos
+"""
+Showcase demos for new and advanced features.
+
+- demo_shaders.py - GLSL shader effects
+- demo_rotation.py - Transform rotation and origin
+- demo_alignment.py - 9-point alignment system
+- demo_animation_chain.py - Animation Chain/Group patterns
+"""