feat: add PyKatha story-driven Python learning prototype

[Shrikant-sharma-9]

Summary

Introduces PyKatha, a story-driven Python learning prototype that teaches beginner control-flow concepts through narrative, reasoning, discovery, and practice.

Learning Flow

Story → Thinking Challenge → Secret Reveal → Practice → Moral

The prototype currently teaches:

• if statements
• while loops
• for loops

through three complete stories:

• Rabbit and the Moon
• Crow and the Pebble
• Turtle and the Garden

What is Included

• Story reading experience
• Five reasoning questions per story
• Progressive thinking challenges
• Step-by-step hidden-logic reveal
• Python concept discovery
• Interactive option-based practice
• Immediate practice feedback
• Moral / lesson page
• Responsive storybook-inspired UI
• Reusable story data structure
• Three complete story-based case studies

Documentation

Documentation is included alongside the implementation:

• README.md — project overview and setup
• context.md — current project state and implementation context
• docs/PRODUCT.md — product goals and scope
• docs/ARCHITECTURE.md — application structure and technical architecture
• docs/LEARNING_FLOW.md — complete learner journey
• docs/STORY_AUTHORING.md — how to create and maintain stories
• docs/CASE_STUDIES.md — current story/concept case studies
• docs/DEVELOPMENT.md — development and verification workflow
• docs/DECISIONS.md — important implementation decisions

Verification

• npm run lint passes
• npm run build passes
• All three story flows were manually verified
• Story IDs and routes were audited
• Documentation was reviewed against the final implementation

Current Limitations

• Practice uses predefined outputs rather than executing arbitrary Python.
• Progress is not persisted.
• Story content is currently hand-authored.
• The current MVP contains three concepts.

Design Goal

The prototype is designed to make Python concepts discoverable through stories rather than introducing syntax first.

The intended learning pattern is:

Experience → Observe → Reason → Discover → Practice → Reflect

The implementation and authoring structure are documented so future contributors can add stories and concepts without rebuilding the core learning flow.