Add coloring-book-prompt generator tool with OpenAI/Claude support and Windows packaging

[RadDad87]

Motivation

• Add a small CLI tool to generate high-quality, print-friendly coloring-book prompts using LLMs and provide an easy Windows packaging/launcher workflow.
• Support OpenAI by default while allowing optional use of Anthropic Claude via --provider claude for flexibility.

Description

• Add new tool at tools/coloring-book-generator including generator.py, a CLI that builds a constrained coloring-book prompt and can call OpenAI (generate_with_openai) or Anthropic (generate_with_claude) based on flags and environment variables.
• Provide environment handling via .env.example and load_dotenv_if_present to populate OPENAI_API_KEY and ANTHROPIC_API_KEY without requiring external dotenv dependency.
• Add Windows helper scripts: cbpp.bat launcher that prefers a packaged dist\cbpp.exe, build_exe.bat to build a single-file EXE with pyinstaller, and package_zip.bat to assemble a distributable ZIP containing the EXE and helpers.
• Include README.md with usage and packaging instructions, requirements.txt listing openai, anthropic, and pyinstaller, and a .gitignore to exclude build artifacts and the .env file.

Testing

• No automated tests were added or executed as part of this change.

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Codex Task

[RadDad87]

test