## Description
Extracts local compression strategy accounting out of
`CompressionFeedback` into a pure cache-domain object. This keeps
strategy counters, retrieval-rate math, pruning, and best-strategy
selection independently testable while preserving the existing
`LocalToolPattern` public API.
Closes #
## Type of Change
- [ ] Bug fix (non-breaking change that fixes an issue)
- [ ] New feature (non-breaking change that adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
- [ ] Performance improvement
- [x] Code refactoring (no functional changes)
## Changes Made
- Added `CompressionStrategyOutcomes` as the strategy-outcome domain for
compression/retrieval counters, pruning, retrieval rates, and
recommendation selection.
- Updated `LocalToolPattern` and `CompressionFeedback` to delegate
strategy accounting to that domain while keeping existing fields and
methods intact.
- Added direct unit coverage for strategy outcome math and bounded
pruning behavior.
- Updated the LiteLLM callback hook signature to remain compatible with
current LiteLLM typing and the existing three-argument call shape.
## Testing
- [x] Unit tests pass (`pytest`)
- [x] Linting passes (`ruff check .`)
- [x] Type checking passes (`mypy headroom`)
- [x] New tests added for new functionality
- [ ] Manual testing performed
### Test Output
```text
python -m ruff check .
All checks passed!
python -m ruff format --check .
1095 files already formatted
python -m mypy headroom --ignore-missing-imports
headroom\proxy\server.py:1457: note: By default the bodies of untyped functions are not checked, consider using --check-untyped-defs [annotation-unchecked]
headroom\proxy\server.py:1468: note: By default the bodies of untyped functions are not checked, consider using --check-untyped-defs [annotation-unchecked]
Success: no issues found in 409 source files
python -m pytest tests/test_compression_strategy_outcomes.py tests/test_ccr_feedback.py tests/test_toin_fixes.py tests/test_litellm_callback.py tests/test_compress_api.py::TestLiteLLMCallback -q
collected 54 items
46 passed, 8 skipped in 6.58s
```
## Real Behavior Proof
- Environment: Windows, Python 3.13.13, clean worktree
`C:\git\headroom-pr-slice5`
- Exact command / steps: ran the lint, format, type-check, and focused
pytest commands listed above.
- Observed result: strategy outcome tests and existing
feedback/TOIN/LiteLLM compatibility tests pass; repo-wide lint/type
validation passes.
- Not tested: full pytest suite and Docker/native CI jobs are left to
GitHub Actions.
## Review Readiness
- [x] I have performed a self-review
- [x] This PR is ready for human review
## Checklist
- [x] My code follows the project's style guidelines
- [x] I have performed a self-review of my code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] I have updated the CHANGELOG.md if applicable
## Screenshots (if applicable)
N/A.
## Additional Notes
- Documentation and changelog are N/A for this internal refactor.
- Manual UI testing is N/A; this is cache feedback and integration
callback logic.
- Comment checklist is unchecked because the extracted object is
intentionally straightforward and covered by tests.
