refactor: adopt directive drafter dev5 integrations

[rlippmann]

Summary

Upgrade the Python directive-drafter integrations to context-compiler-directive-drafter==0.2.0dev5 and adopt its provider-neutral fallback profiles and LiteLLM adapter.

Why

Dev5 removes the old public prompt getters and provides the supported LiteLLM fallback adapter. This keeps provider transport, capability probing, fallback parsing, and prompt material owned by the drafter package while preserving Context Compiler as the authority over state.

Example metadata

• Enforcement point: repository maintenance / integration fallback acquisition
• Domain: cross-domain examples
• Technology/runtime: Python, LiteLLM, LiteLLM Proxy, Open WebUI
• Example type: reference integration / repository maintenance
• Does this use directive drafter? should normally be no: Yes, these are specifically directive-drafter integrations.
• Does this derive state from model output? must be no for primary examples: No. Candidate directives still pass through Context Compiler.

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

Commits:

• build: update directive drafter to 0.2.0dev5
• refactor: adopt dev5 fallback profiles and LiteLLM adapter
• test: validate dev5 LiteLLM fallback integration
• test: keep integration tests focused on wiring

Validation: ./scripts/validate_python.sh passed with 210 tests passed and 6 skipped; uv lock --check, Ruff, formatting, mypy, and git diff --check passed.