docs: migrate Python integration examples

[rlippmann]

Summary

Migrate the copied Python integration examples into the role-first example and
reference-integration locations, and update the copied directive-drafter paths
to use context_compiler_directive_drafter.

Why

The scaffold repo has already landed. This follow-up adds the copied Python
integration examples in their intended enforcement-point locations and cleans up
the old experimental directive-drafter references so the copied variants match
the current package split.

Example metadata

• Enforcement point: multiple Python enforcement-point examples plus reference integrations
• Domain: customer support routing, writing assistant, structured intake, and related copied example domains
• Technology/runtime: LiteLLM, Ollama structured output, LiteLLM Proxy, Open WebUI
• Example type: minimal example / reference integration / repository maintenance
• Does this use directive drafter? should normally be no: some copied variants do; primary basic variants remain available
• Does this derive state from model output? must be no for primary examples: no

Checklist

• Repository scaffolding / governance change
• One primary enforcement point
• Explicit authoritative state
• No model-derived state mutation
• Adversarial stub or equivalent test
• Observable runtime behavior change
• Domain vocabulary is natural
• Framework is secondary to the enforcement point
• Docs updated
• Tests/smoke checks added where practical

Notes

Validation run:

• python3 -m py_compile on the copied Python example and reference-integration modules

Migration notes:

• copied directive-drafter variants now import context_compiler_directive_drafter
• old experimental.preprocessor references were removed from the migrated scope
• compatibility-sensitive env var names such as PREPROCESSOR_MODEL were kept unchanged