## Description
Extracts memory-tool golden byte replay and canonicalization from
`headroom.proxy.helpers.apply_session_sticky_memory_tools` into a
focused policy module. The session tracker, skip/deduplication
decisions, and logging remain in the existing helper; the byte-level
replay policy now has direct coverage.
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 `headroom.proxy.memory_golden_policy` for replaying stored
memory golden bytes and canonicalizing fresh memory tool definitions.
- Updated `apply_session_sticky_memory_tools` to delegate golden-byte
decode/canonicalization while preserving tracker and logging behavior.
- Added direct tests for golden replay, invalid/corrupt bytes, non-UTF-8
bytes, and serializer parity with the existing helper.
## 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 pytest tests/test_memory_golden_policy.py tests/test_memory_tool_session_sticky.py tests/test_corrupt_golden_bytes_recovery.py tests/test_issue_728_empty_tools_injection.py
50 passed in 0.87s
python -m ruff check .
All checks passed!
python -m ruff format --check .
1069 files already formatted
python -m mypy headroom --ignore-missing-imports
Success: no issues found in 410 source files
gitleaks protect --staged --no-banner --redact
no leaks found
```
## Real Behavior Proof
- Environment: Windows, Python 3.13.13, clean worktree from
`headroomlabs/main` at `d2170b19`.
- Exact command / steps: Ran targeted memory golden replay/sticky
injection/corrupt-byte regression tests plus ruff, ruff-format, mypy,
and staged gitleaks scan.
- Observed result: All targeted tests and local gates passed; staged
secret scan found no leaks.
- Not tested: Full Docker/native wrapper CI locally; covered by
repository CI.
## 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
- [x] 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 updates are not applicable for this internal
refactor. The push reported existing default-branch Dependabot
vulnerabilities; this PR's staged gitleaks scan passed and CI security
checks are expected to validate the branch.
Co-authored-by: Tejas Chopra <chopratejas@gmail.com>
